Medical Abbreviations Starting With "A"

This page lists 488 medical abbreviations starting with "A", each with its full form and a plain-English meaning. Where one abbreviation has more than one common meaning, each meaning has its own row — context in the chart is what tells them apart. Terms flagged ⚠ Error-prone are on recognised error-prone lists and should be written out in full. Use the filter box to narrow this list, the search on the main guide to search all 5,715 entries, or jump to another letter:

B C D E F G H I J K L M N 0–9 O P Q R S T U V W X Y Z

Abbreviation	Full form	What it means	Used in
A&O	alert and oriented	Awake and aware of person, place and time	Vitals & Assessment Nursing
A&O x4	alert and oriented times four (person place time situation)	Full orientation documentation	Neurology Nursing General Medical
A&P	auscultation and percussion	Listening to and tapping the body during examination	Vitals & Assessment
A-a gradient	alveolar-arterial gradient	Difference between oxygen in the air sacs and in artery blood	Respiratory
A-line	A-line (arterial line shorthand)	Arterial catheter shorthand	Emergency & Critical Care Nursing
a.c.	ante cibum (before meals)	Latin charting for before meals	Prescription & Medication Orders Nursing
a.m.	ante meridiem (morning)	Charting shorthand for morning	General Medical Nursing
A/P	assessment and plan	Clinician's conclusions and plan for each problem	General Medical
A1C	hemoglobin A1C	Blood test showing average sugar over about three months	Laboratory Endocrinology
A1GDM	class A1 gestational diabetes (diet)	Diet-controlled gestational diabetes	Obstetrics & Gynecology Endocrinology
A2GDM	class A2 gestational diabetes (medication)	Medicine-treated gestational diabetes	Obstetrics & Gynecology Endocrinology
AAA	abdominal aortic aneurysm	Bulging weak spot in the aorta in the abdomen	Cardiology Surgery
AAA repair	abdominal aortic aneurysm repair	Operation fixing a swollen main artery in the abdomen	Surgery Cardiology
AAP hyperbili	AAP hyperbilirubinemia guideline	National newborn jaundice guideline	Pediatrics
AAROM	active-assisted range of motion	Joint movement a person performs with some help	Musculoskeletal
AAT	alpha-1 antitrypsin	Protein that protects the lungs from enzyme damage	Respiratory Laboratory
AATD	alpha-1 antitrypsin deficiency	Inherited lack of a lung-protective protein	Respiratory
ABA	applied behavior analysis	Behaviour therapy using learning principles, often for autism	Psychiatry Pediatrics
ABAS	Adaptive Behavior Assessment System	Daily-living skills rating system	Psychiatry Pediatrics
ABC	airway, breathing, circulation	First priorities in emergency assessment	Emergency & Critical Care
ABCD	airway, breathing, circulation, disability	Emergency assessment priorities including brain function	Emergency & Critical Care
ABCDE	airway, breathing, circulation, disability, exposure	Structured emergency assessment sequence	Emergency & Critical Care
ABE	acute bilirubin encephalopathy	Acute brain effects of extreme jaundice	Pediatrics Neurology Emergency & Critical Care
ABEMA	abemaciclib (chart shorthand)	CDK4/6 blocker shorthand	Prescription & Medication Orders Hematology & Oncology
Abeta42	amyloid beta 42 (CSF/blood)	Alzheimer marker peptide	Neurology Laboratory
ABG	arterial blood gas	Blood test from an artery measuring oxygen, carbon dioxide and acidity	Respiratory Laboratory
ABI	abiraterone (chart shorthand)	Prostate cancer hormone pill shorthand	Prescription & Medication Orders Hematology & Oncology
ABI	ankle-brachial index	Ratio comparing ankle and arm blood pressures to check leg flow	Cardiology
ABMR	antibody-mediated rejection (activity)	Antibody attack on a transplant	Renal & Nephrology Surgery Laboratory
ABO	ABO blood group system	Main blood group classification, A, B, AB or O	Laboratory Hematology & Oncology
ABO incompatible	ABO-incompatible transplant (program)	Transplant across blood groups with preparation	Renal & Nephrology Surgery
ABPA	allergic bronchopulmonary aspergillosis	Allergic lung reaction to a common fungus in the airways	Respiratory
ABPI	ankle-brachial pressure index	Ratio comparing blood pressure at ankle and arm	Cardiology Vitals & Assessment
ABR	auditory brainstem response (test)	Hearing pathway test — test	Neurology Pediatrics
absence	absence seizure (type)	Brief staring seizure — type	Neurology Pediatrics
ABSSSI	acute bacterial skin and skin structure infection	Regulatory term for serious skin infections	Infectious Disease
ABVD	doxorubicin, bleomycin, vinblastine, dacarbazine	Combination chemotherapy regimen for Hodgkin lymphoma, from drug initials	Hematology & Oncology Prescription & Medication Orders
ABVS	automated breast volume scanner	Automated whole-breast ultrasound	Radiology & Imaging
ABx	antibiotics	Medicines treating bacterial infections	Prescription & Medication Orders Infectious Disease
AC	abdominal circumference	Ultrasound measurement around a baby's abdomen before birth	Obstetrics & Gynecology Radiology & Imaging
AC	anterior chamber (eye)	Fluid space at the front of the eye	General Medical Surgery
AC	before meals	Before eating, from Latin ante cibum	Prescription & Medication Orders
AC	doxorubicin cyclophosphamide	Breast cancer chemotherapy combination	Hematology & Oncology Prescription & Medication Orders
AC fetal	abdominal circumference (fetal ultrasound)	Fetal belly size measurement	Obstetrics & Gynecology Radiology & Imaging
ACA	anterior cerebral artery	Artery supplying the front inner part of the brain	Neurology
ACA	anticentromere antibody	Antibody linked to limited scleroderma	Laboratory
ACA anatomy	anterior cerebral artery (anatomy)	Artery feeding the front-inner brain	Neurology
ACALA	acalabrutinib (chart shorthand)	BTK blocker pill shorthand	Prescription & Medication Orders Hematology & Oncology
access flow	access flow (Qa surveillance)	Measured blood flow through a dialysis access	Renal & Nephrology Radiology & Imaging
access port	access (implantable port)	Placing a needle into an implanted port	Nursing Hematology & Oncology
accidental extubation	accidental extubation (event)	Unplanned tube removal by movement or care	Respiratory Emergency & Critical Care Nursing
ACDF	anterior cervical discectomy and fusion	Neck disc removal and fusion from the front	Surgery Neurology Musculoskeletal
ACE	angiotensin-converting enzyme	Enzyme involved in controlling blood pressure	Cardiology
ACE-III	Addenbrooke's Cognitive Examination III	Detailed bedside cognitive test	Neurology Psychiatry
ACEI	angiotensin-converting enzyme inhibitor	Blood pressure medicine blocking an enzyme that tightens vessels	Prescription & Medication Orders Cardiology Renal & Nephrology
ACEs	adverse childhood experiences	Potentially traumatic events occurring before age eighteen	Psychiatry Pediatrics
ACG	angle-closure glaucoma	Raised eye pressure from a blocked drainage angle	General Medical Emergency & Critical Care
Achilles repair	Achilles tendon repair	Stitching a torn heel tendon	Surgery Musculoskeletal
acholic stool	acholic stools (pale sign)	Pale stools suggesting blocked bile flow	Pediatrics Gastroenterology
AChR ab	acetylcholine receptor antibody	Main myasthenia gravis antibody	Neurology Laboratory
acinus	acinus (pulmonary anatomy)	Smallest lung unit beyond the terminal bronchiole	Respiratory
ACIOL	anterior chamber intraocular lens	Lens implant placed in the front chamber	General Medical Surgery
ACL	anterior cruciate ligament	Knee ligament preventing forward shin movement	Musculoskeletal
aCL	anticardiolipin antibody	Antiphospholipid antibody linked to clots and pregnancy loss	Laboratory Hematology & Oncology Obstetrics & Gynecology
ACL recon	anterior cruciate ligament reconstruction	Rebuilding the knee's central ligament	Surgery Musculoskeletal
ACLF	acute-on-chronic liver failure	Sudden worsening in long-term liver disease	Gastroenterology Emergency & Critical Care
ACLS	advanced cardiovascular life support	Advanced emergency care for cardiac arrest and dangerous rhythms	Cardiology Emergency & Critical Care
ACOM	anterior communicating artery	Small connecting artery at the brain front	Neurology
ACQ	Asthma Control Questionnaire	Asthma control measure	Respiratory
ACR	albumin-to-creatinine ratio	Urine test measuring protein leakage from kidneys	Renal & Nephrology Laboratory
ACR	American College of Radiology (appropriateness context)	Radiology body issuing imaging guidance	Radiology & Imaging General Medical
ACR20	American College of Rheumatology 20 percent response	Rheumatoid arthritis trial improvement threshold	Musculoskeletal
acrodermatitis	acrodermatitis enteropathica (zinc)	Zinc deficiency rash and diarrhea disorder	Pediatrics Gastroenterology
ACS	acute compartment syndrome	Dangerous pressure build-up within a muscle compartment	Musculoskeletal Emergency & Critical Care
ACS	acute coronary syndrome	Sudden reduced blood flow to the heart, including heart attack	Cardiology
ACS	antenatal corticosteroids (course)	Steroid course maturing fetal lungs — course	Obstetrics & Gynecology Prescription & Medication Orders Pediatrics
ACT	acceptance and commitment therapy	Therapy using acceptance and mindfulness toward personal values	Psychiatry
ACT	activated clotting time	Bedside test of blood clotting during procedures	Laboratory Cardiology Surgery
ACT	assertive community treatment	Team-based community care for severe mental illness	Psychiatry
ACT	Asthma Control Test	Asthma control questionnaire	Respiratory Vitals & Assessment Pediatrics
ACT child	Asthma Control Test (childhood version)	Asthma control questionnaire — version	Pediatrics Respiratory
ACTH	adrenocorticotropic hormone	Pituitary hormone stimulating the adrenal glands	Laboratory Endocrinology
active SI	active suicidal ideation	Thoughts of killing oneself	Psychiatry
acuity	patient acuity (severity level)	Measure of how much care a patient needs	Nursing General Medical
ACV	acyclovir (chart shorthand)	Herpes antiviral chart shorthand	Prescription & Medication Orders Infectious Disease
acyanotic	acyanotic heart defects (group)	Heart defects without blue discoloration	Pediatrics Cardiology
AD	Alzheimer disease	Progressive brain disease causing memory loss and dementia	Neurology Psychiatry
AD ⚠ Error-prone	right ear	The right ear, from Latin auris dextra	General Medical
AD biomarkers	Alzheimer biomarkers (ATN)	Amyloid tau neurodegeneration framework markers	Neurology Laboratory
AD8	AD8 dementia screening interview	Eight-question informant dementia screen	Neurology Psychiatry
ADA	American Diabetes Association diet	Meal plan following diabetes association guidance	Endocrinology Nursing
ADA diet	American Diabetes Association diet	Diabetes meal plan shorthand	Nursing Endocrinology
Adams test	Adams forward bend test (scoliosis)	Bending screen for spinal curvature	Pediatrics Musculoskeletal
ADAMTS13	ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13)	Enzyme measured when TTP is suspected	Laboratory Hematology & Oncology
ADAPT	accelerated diagnostic protocol (chest pain)	Two-hour chest pain assessment pathway	Cardiology Emergency & Critical Care
ADAS-Cog	Alzheimer Disease Assessment Scale Cognitive	Cognition measure in dementia trials	Neurology Psychiatry
ADC	antibody-drug conjugate	Antibody carrying a chemotherapy payload to cancer cells	Prescription & Medication Orders Hematology & Oncology
ADC	apparent diffusion coefficient	MRI map quantifying water diffusion, paired with DWI	Radiology & Imaging Neurology
ADC	automated dispensing cabinet	Secure electronic cabinet storing medicines on wards	Nursing Prescription & Medication Orders
Addison	Addison's disease	Adrenal glands making too little cortisol	Endocrinology
ADEM	acute disseminated encephalomyelitis	Brief widespread immune inflammation of brain and cord	Neurology
adeno	adenomyosis (shorthand)	Womb lining tissue inside the muscle wall shorthand	Obstetrics & Gynecology
Adeno	adenosine	Medicine briefly slowing the heart's electrical conduction	Prescription & Medication Orders Cardiology Emergency & Critical Care
adenoidectomy	adenoidectomy (procedure)	Removal of the adenoids	Surgery Pediatrics
adenoiditis	adenoiditis (infection)	Inflamed adenoids	Pediatrics Infectious Disease Surgery
adenoma sebaceum	facial angiofibromas (tuberous sclerosis)	Facial bumps of tuberous sclerosis	Pediatrics Neurology
adenotonsillectomy	adenotonsillectomy (procedure)	Tonsil and adenoid removal — procedure	Pediatrics Surgery Respiratory
ADH	antidiuretic hormone	Hormone telling kidneys to conserve water	Laboratory Endocrinology Renal & Nephrology
ADHD	attention-deficit/hyperactivity disorder	Condition with inattention, hyperactivity and impulsivity	Psychiatry Pediatrics
ADI-R	Autism Diagnostic Interview Revised	Parent interview for autism assessment	Pediatrics Psychiatry
Adie	Adie tonic pupil	Slow-reacting dilated pupil, usually benign	Neurology
adjustment	adjustment disorder (diagnosis)	Outsized reaction to a stressor — diagnosis	Psychiatry
ADL	activities of daily living	Basic self-care tasks such as eating, bathing and dressing	General Medical Nursing
admit to	admit to (order phrase)	Order assigning the patient to a service or unit	Nursing General Medical
ADOS	Autism Diagnostic Observation Schedule	Structured autism assessment	Pediatrics Psychiatry
ADPKD	autosomal dominant polycystic kidney disease	Inherited adult form of cystic kidney disease	Renal & Nephrology
ADR	adverse drug reaction	Harmful or unwanted effect of a medicine	General Medical Prescription & Medication Orders
adrenal crisis	adrenal crisis (emergency)	Cortisol-lack shock emergency	Emergency & Critical Care Endocrinology
adrenalectomy	adrenalectomy (procedure)	Removal of an adrenal gland	Surgery Endocrinology
adrenalectomy lap	laparoscopic adrenalectomy	Keyhole removal of an adrenal gland	Surgery Endocrinology
adrenarche	premature adrenarche (early)	Early adrenal puberty signs	Pediatrics Endocrinology
ADT	androgen deprivation therapy (drug)	Hormone therapy lowering testosterone in prostate cancer	Prescription & Medication Orders Hematology & Oncology
AdV	adenovirus	Virus causing respiratory, eye and gut infections	Infectious Disease Laboratory
AdV-F	enteric adenovirus	Gut adenovirus types causing diarrhea	Infectious Disease Gastroenterology Laboratory
advance directive	advance directive (document)	Legal document stating future care wishes	Nursing General Medical
AE	adverse event	Unfavourable medical occurrence during treatment	General Medical Prescription & Medication Orders
AED	antiepileptic drug	Medicine class used to prevent seizures	Neurology Prescription & Medication Orders
AED	automated external defibrillator	Portable device that shocks the heart in cardiac arrest	Cardiology Emergency & Critical Care
aEEG	amplitude-integrated EEG (cerebral monitor)	Simplified brain monitor used in NICU	Pediatrics Neurology
AEIOU	AEIOU (dialysis indications mnemonic)	Acidosis, electrolytes, ingestions, overload, uremia indications	Renal & Nephrology Emergency & Critical Care
AERD	aspirin-exacerbated respiratory disease	Asthma and nasal polyps worsened by aspirin-like medicines	Respiratory
AF	atrial fibrillation	Irregular, rapid heart rhythm from the upper chambers	Cardiology
AFB	acid-fast bacilli	Bacteria, including TB, that hold a special stain in the lab	Respiratory Laboratory Infectious Disease
AFC	antral follicle count	Ultrasound count of resting follicles	Obstetrics & Gynecology Radiology & Imaging
affect MSE	affect (mental status element)	Observed emotional expression	Psychiatry
AFG	anidulafungin (chart shorthand)	Echinocandin antifungal chart shorthand	Prescription & Medication Orders Infectious Disease
AFI	amniotic fluid index	Ultrasound measurement of the fluid around the baby	Obstetrics & Gynecology Radiology & Imaging
AFL	atrial flutter	Fast, regular fluttering rhythm in the upper heart chambers	Cardiology
AFLP	acute fatty liver of pregnancy	Rare liver failure of late pregnancy	Obstetrics & Gynecology Gastroenterology Emergency & Critical Care
AFO	ankle-foot orthosis (device)	Brace supporting the ankle — device	Musculoskeletal Neurology Nursing
AFP	alpha-fetoprotein	Protein marker for certain liver and germ cell tumours	Laboratory Hematology & Oncology Gastroenterology Obstetrics & Gynecology
AFP tumor	alpha-fetoprotein (tumor)	Marker for liver and germ cell tumors — tumor	Pediatrics Laboratory Hematology & Oncology
AG	anion gap	Calculated gap between measured blood electrolytes	Laboratory Emergency & Critical Care
AGA	appropriate for gestational age	Size within the expected range for the stage of pregnancy	Obstetrics & Gynecology Pediatrics
AGB	adjustable gastric band	Weight-loss operation placing a band around the stomach	Surgery Gastroenterology
AGC	atypical glandular cells (Pap result)	Abnormal glandular Pap finding	Obstetrics & Gynecology Laboratory
AGEP	acute generalized exanthematous pustulosis	Sudden widespread pustular drug rash	General Medical
agoraphobia	agoraphobia (diagnosis)	Fear of escape-difficult places — diagnosis	Psychiatry
aGVHD	acute graft-versus-host disease	Early donor-versus-host attack after transplant	Hematology & Oncology
AH	auditory hallucinations	Hearing sounds or voices that are not there	Psychiatry
AHG	anti-human globulin	Reagent used in Coombs testing	Laboratory Hematology & Oncology
AHI	apnea-hypopnea index	Number of breathing pauses or reductions per hour of sleep	Respiratory
AHI child	apnea-hypopnea index (pediatric thresholds)	Sleep apnea event rate — pediatric	Pediatrics Respiratory
AHT	abusive head trauma	Head injury in a child caused by abuse	Pediatrics Neurology Emergency & Critical Care
AHTR	acute hemolytic transfusion reaction	Dangerous rapid red cell destruction after wrong blood	Hematology & Oncology Emergency & Critical Care
aHUS	atypical hemolytic uremic syndrome	Complement-driven kidney failure syndrome	Pediatrics Renal & Nephrology Hematology & Oncology
AI	aortic insufficiency	Leaking aortic valve; another name for aortic regurgitation	Cardiology
AI	aromatase inhibitor (drug class)	Estrogen-lowering pill class for breast cancer	Prescription & Medication Orders Hematology & Oncology Endocrinology
AICA	anterior inferior cerebellar artery	Artery feeding the front cerebellum	Neurology
AIDP	acute inflammatory demyelinating polyneuropathy	Acute immune damage to peripheral nerve coverings	Neurology
AIDS	acquired immunodeficiency syndrome	Advanced stage of HIV infection	Infectious Disease
AIDS-defining illness	AIDS-defining condition	Illness marking advanced HIV disease	Infectious Disease
AIH	autoimmune hepatitis	Liver inflammation caused by the immune system	Gastroenterology
AIHA	autoimmune hemolytic anemia	Antibody destruction of one's own red cells	Hematology & Oncology
AIIR	airborne infection isolation room	Negative-pressure isolation room	Nursing Infectious Disease Emergency & Critical Care
AIMS exam	Abnormal Involuntary Movement Scale (exam)	Movement side-effect check — examination	Psychiatry Neurology
AIMS65	AIMS65 score	Upper GI bleed mortality score	Gastroenterology Emergency & Critical Care
AIN	acute interstitial nephritis	Kidney inflammation between the tubules	Renal & Nephrology
AIN	anal intraepithelial neoplasia	Precancerous anal change	Gastroenterology Obstetrics & Gynecology
AIN	anterior interosseous nerve	Deep branch of the median nerve	Neurology Musculoskeletal
AION	anterior ischemic optic neuropathy	Optic nerve head stroke	General Medical Neurology
AIP	acute interstitial pneumonia	Rapid lung scarring illness resembling ARDS without a clear cause	Respiratory
air enema	pneumatic reduction (intussusception)	Air pressure untelescoping the bowel	Pediatrics Radiology & Imaging Surgery
airborne precautions	airborne precautions (isolation)	Negative-pressure room and fitted mask for airborne germs	Nursing Infectious Disease Respiratory
airway assessment	airway assessment (LEMON)	Look, evaluate, Mallampati, obstruction, neck difficulty screen	Emergency & Critical Care
AIS	androgen insensitivity syndrome	Genetic condition affecting sexual development in people with XY chromosomes	Obstetrics & Gynecology Endocrinology Pediatrics
AK	actinic keratosis	Rough sun-damaged skin patch that can progress	General Medical
AKA	above-knee amputation	Removal of the leg above the knee	Surgery
akathisia	akathisia (side-effect)	Inner restlessness from medicines — side-effect	Psychiatry Prescription & Medication Orders
AKI	acute kidney injury	Sudden decline in kidney function	Renal & Nephrology Emergency & Critical Care
AKIN	Acute Kidney Injury Network criteria	AKI staging criteria	Renal & Nephrology Emergency & Critical Care
AL	amyloid light chain	Protein deposit disease from abnormal plasma cells	Hematology & Oncology
Alb	albumin	Main protein made by the liver, measured in blood	Laboratory Gastroenterology
ALBI	albumin-bilirubin grade	Score grading liver function from two blood tests	Gastroenterology Laboratory
ALC	absolute lymphocyte count	Calculated number of lymphocytes in blood	Laboratory Hematology & Oncology
ALD	alcoholic liver disease	Liver damage caused by alcohol	Gastroenterology
ALEC	alectinib (chart shorthand)	ALK blocker pill shorthand	Prescription & Medication Orders Hematology & Oncology
ALF	acute liver failure	Sudden severe liver failure	Gastroenterology Emergency & Critical Care
ALI	acute limb ischemia	Sudden limb artery blockage threatening the limb	Cardiology Emergency & Critical Care
ALI	acute lung injury	Sudden lung damage causing low oxygen; older term related to ARDS	Respiratory Emergency & Critical Care
ALIF	anterior lumbar interbody fusion	Back fusion from the front	Surgery Musculoskeletal
ALK	anaplastic lymphoma kinase	Gene change targeted by some cancer medicines	Hematology & Oncology Laboratory
ALK	anterior lamellar keratoplasty	Partial front-layer cornea transplant	General Medical Surgery
ALL	acute lymphoblastic leukemia	Fast-growing cancer of lymphoid white cells	Hematology & Oncology
ALL child	childhood acute lymphoblastic leukemia ()	Commonest childhood cancer	Pediatrics Hematology & Oncology
Allen test	Allen's test	Hand test of collateral circulation before arterial sampling	Vitals & Assessment Respiratory
allo-HSCT	allogeneic hematopoietic stem cell transplant	Stem cell transplant from a donor	Hematology & Oncology
alloimmunization	red cell alloimmunization (pregnancy)	Mother making antibodies against fetal blood cells	Obstetrics & Gynecology Laboratory Hematology & Oncology
ALND	axillary lymph node dissection	Removal of lymph nodes from the armpit	Surgery Hematology & Oncology
ALOS	average length of stay	Mean hospital stay across patients	General Medical
ALP	alkaline phosphatase	Enzyme related to liver and bone, measured in blood	Laboratory Gastroenterology
ALS	advanced life support	Advanced emergency resuscitation care	Emergency & Critical Care
ALS	amyotrophic lateral sclerosis	Progressive disease weakening muscles by damaging motor nerves	Neurology
ALSFRS	ALS Functional Rating Scale (score)	ALS function score — score	Neurology
ALSFRS-R	ALS Functional Rating Scale Revised	ALS function score	Neurology
ALT	alanine aminotransferase	Liver enzyme measured in blood	Laboratory Gastroenterology
ALT	argon laser trabeculoplasty	Older laser treatment for glaucoma	General Medical Surgery
ALT flap	anterolateral thigh flap	Thigh tissue flap for reconstruction	Surgery
ALTE	apparent life-threatening event	Older term for a frightening episode in an infant that resolves	Pediatrics Emergency & Critical Care
altruistic donor	nondirected donor (altruistic)	Donor giving without a named recipient	Renal & Nephrology Surgery
alveolar graft	alveolar bone graft (cleft)	Bone filling the gum cleft in childhood	Pediatrics Surgery
alveoli	alveoli (anatomy)	Tiny air sacs where gas exchange happens	Respiratory
AM child	abdominal migraine (childhood)	Episodic stomach pain migraine equivalent	Pediatrics Gastroenterology Neurology
AM labs	morning labs (batch)	Routine early-morning blood tests	Nursing Laboratory
AMA	against medical advice	Leaving or refusing care contrary to medical recommendation	General Medical
AMA	antimitochondrial antibody	Antibody strongly linked to primary biliary cholangitis	Laboratory Gastroenterology
AMA discharge	against medical advice discharge	Patient leaving despite medical recommendation	Nursing Emergency & Critical Care General Medical
AMAN	acute motor axonal neuropathy	Guillain-Barré variant damaging motor axons	Neurology
Amb	ambulate	To walk or move about	Nursing
AmB	amphotericin B (chart shorthand)	Broad antifungal chart shorthand	Prescription & Medication Orders Infectious Disease
amb ad lib	ambulate as desired	Walk freely order	Nursing
amblyopia	amblyopia (lazy eye)	Reduced vision from disuse in childhood	Pediatrics Neurology
AMD	age-related macular degeneration	Eye disease damaging central vision in older people	General Medical
AMH	anti-Mullerian hormone	Hormone marker of ovarian reserve	Endocrinology Laboratory Obstetrics & Gynecology
AMH	anti-Müllerian hormone	Hormone reflecting the number of eggs remaining in the ovaries	Obstetrics & Gynecology Endocrinology Laboratory
AMH fertility	anti-Müllerian hormone (fertility)	Ovarian reserve blood test — fertility	Obstetrics & Gynecology Laboratory
aminophylline	aminophylline (asthma)	Older infusion bronchodilator — asthma	Pediatrics Respiratory Prescription & Medication Orders
Amio	amiodarone	Medicine controlling abnormal heart rhythms	Prescription & Medication Orders Cardiology
AMK	amikacin (chart shorthand)	Aminoglycoside antibiotic chart shorthand	Prescription & Medication Orders Infectious Disease
AML	acute myeloid leukemia	Fast-growing cancer of myeloid white cells	Hematology & Oncology
AML child	childhood acute myeloid leukemia ()	Myeloid leukemia of childhood	Pediatrics Hematology & Oncology
AML kidney child	renal angiomyolipoma (tuberous)	Kidney fat-muscle tumor of tuberous sclerosis	Pediatrics Renal & Nephrology Neurology
amnio	amniocentesis (genetic testing use)	Fluid sampling test for fetal genetic conditions	Laboratory Obstetrics & Gynecology
Amp	ampule	Small sealed glass container of injectable medicine	Prescription & Medication Orders
amputation AKA	above-knee amputation (procedure)	Leg removal above the knee — procedure	Surgery
AMR	antimicrobial resistance (transplant/infection)	Resistance of microbes to treatment drugs	Infectious Disease General Medical
AMS	altered mental status	Change in awareness, thinking or behaviour from usual	Neurology Psychiatry
AMTS	Abbreviated Mental Test Score	Short bedside test of memory and orientation	Neurology Psychiatry
amygdala	amygdala (anatomy)	Almond-shaped emotion center	Neurology Psychiatry
AN	anorexia nervosa	Eating disorder with restriction, low weight and fear of gaining	Psychiatry
ANA	anastrozole (chart shorthand)	Aromatase inhibitor shorthand — note ANA also means antinuclear antibody	Prescription & Medication Orders Hematology & Oncology
ANA	antinuclear antibody	Immune antibody test used in autoimmune conditions	Laboratory Musculoskeletal
anaphylaxis action	anaphylaxis action plan (document)	Written allergy emergency plan	Pediatrics Nursing
anaphylaxis child	pediatric anaphylaxis (presentation)	Severe allergic reaction in children	Pediatrics Emergency & Critical Care Infectious Disease
ANC	absolute neutrophil count	Calculated number of neutrophils in blood	Laboratory Hematology & Oncology
ANC	antenatal care	Health care during pregnancy before birth	Obstetrics & Gynecology
ANC clozapine	absolute neutrophil count (clozapine monitoring)	White cell count gating clozapine supply	Psychiatry Laboratory
ANCA	antineutrophil cytoplasmic antibody	Antibody linked to small-vessel vasculitis	Laboratory Renal & Nephrology Respiratory
ancillary test	ancillary test (brain death)	Confirmatory test when the exam cannot be completed	Neurology Emergency & Critical Care Radiology & Imaging
AND	allow natural death	Order framing withholding CPR as allowing natural death	Nursing Emergency & Critical Care
aneurysm access	access aneurysm (complication)	Ballooned weak segment of a fistula	Renal & Nephrology Surgery
Angelman	Angelman syndrome (neurodevelopmental)	Happy-puppet genetic developmental syndrome	Neurology Pediatrics
Angio	angiography	X-ray imaging of vessels using contrast	Radiology & Imaging Cardiology
angioplasty access	access angioplasty (dialysis)	Balloon opening of a narrowed dialysis access	Radiology & Imaging Renal & Nephrology Surgery
anion gap	anion gap (acid-base calculation)	Calculated gap used to classify metabolic acidosis	Laboratory Emergency & Critical Care Renal & Nephrology
aniridia	aniridia (absent iris)	Missing iris from birth	Pediatrics Renal & Nephrology
anisocoria	anisocoria (finding)	Unequal pupil sizes — finding	Neurology
anisometropia	anisometropia (unequal focus)	Different prescriptions between the eyes	Pediatrics
ankle fusion	ankle arthrodesis (fusion)	Fusing the ankle joint	Surgery Musculoskeletal
ankle pumps	ankle pumps (exercise)	Foot flexing exercise promoting circulation	Nursing Musculoskeletal
ANNA	antineuronal nuclear antibody	Paraneoplastic antibody group in nerve syndromes	Laboratory Neurology
ANS	autonomic nervous system	Nerve system controlling automatic body functions	Neurology
antalgic gait	antalgic gait (pain)	Short-stance painful walking	Pediatrics Musculoskeletal
anterior repair	anterior colporrhaphy (cystocele)	Front wall repair for bladder prolapse	Obstetrics & Gynecology Surgery
anti-AChR	anti-acetylcholine receptor antibody	Antibody causing myasthenia gravis	Laboratory Neurology
anti-C	anti-C antibody	Red cell antibody of the Rh system	Laboratory Hematology & Oncology
Anti-CCP	anti-cyclic citrullinated peptide	Antibody test supporting rheumatoid arthritis	Laboratory Musculoskeletal
anti-D	anti-D antibody	Antibody against the Rh D antigen	Laboratory Hematology & Oncology Obstetrics & Gynecology
anti-DNase B	anti-deoxyribonuclease B	Antibody test for recent streptococcal infection	Laboratory Infectious Disease
anti-dsDNA	anti-double-stranded DNA antibody	Antibody strongly linked to lupus	Laboratory
anti-E	anti-E antibody	Red cell antibody of the Rh system	Laboratory Hematology & Oncology
anti-Fya	anti-Duffy a antibody	Red cell antibody of the Duffy system	Laboratory Hematology & Oncology
anti-Fyb	anti-Duffy b antibody	Red cell antibody of the Duffy system	Laboratory Hematology & Oncology
Anti-GAD	glutamic acid decarboxylase antibody	Autoimmune marker antibody in type 1 diabetes	Endocrinology Laboratory
Anti-GBM	anti-glomerular basement membrane antibody	Antibody attacking kidney and lung filters	Laboratory Renal & Nephrology Respiratory
anti-GQ1b	anti-GQ1b antibody (Miller Fisher)	Antibody of the eye-movement variant	Neurology Laboratory
anti-HAV	hepatitis A antibody	Marker of hepatitis A immunity	Laboratory Infectious Disease Gastroenterology
anti-HBc	hepatitis B core antibody	Marker of past or current hepatitis B infection	Laboratory Infectious Disease
anti-HBe	hepatitis B e antibody	Antibody appearing as hepatitis B activity falls	Laboratory Infectious Disease
anti-HBs	hepatitis B surface antibody	Protective antibody after vaccination or recovery	Laboratory Infectious Disease
anti-HCV	hepatitis C antibody	Screening marker for hepatitis C exposure	Laboratory Infectious Disease Gastroenterology
anti-Hu	anti-Hu antibody	Paraneoplastic antibody linked to small cell lung cancer	Laboratory Neurology Hematology & Oncology
anti-IF	anti-intrinsic factor antibody	Specific antibody in pernicious anemia	Laboratory Hematology & Oncology
anti-Jka	anti-Kidd a antibody	Antibody notorious for delayed transfusion reactions	Laboratory Hematology & Oncology
anti-Jkb	anti-Kidd b antibody	Kidd system red cell antibody	Laboratory Hematology & Oncology
Anti-Jo-1	anti-Jo-1 antibody	Autoimmune antibody linked to muscle inflammation	Laboratory Musculoskeletal
anti-K	anti-Kell antibody	Potent red cell antibody causing hemolysis	Laboratory Hematology & Oncology
Anti-La	anti-La/SSB antibody	Autoimmune antibody linked to Sjogren's syndrome	Laboratory Musculoskeletal
anti-Lea	anti-Lewis a antibody	Usually insignificant cold red cell antibody	Laboratory Hematology & Oncology
anti-Leb	anti-Lewis b antibody	Lewis system red cell antibody	Laboratory Hematology & Oncology
anti-M	anti-M antibody	Usually cold-reacting red cell antibody	Laboratory Hematology & Oncology
anti-MOG	anti-myelin oligodendrocyte glycoprotein antibody	Antibody in a demyelinating disease of brain and eyes	Laboratory Neurology
anti-MuSK	muscle-specific kinase antibody	Antibody found in a form of myasthenia gravis	Laboratory Neurology
anti-N	anti-N antibody	Cold-reacting red cell antibody	Laboratory Hematology & Oncology
anti-NMDA	anti-NMDA receptor antibody	Antibody causing autoimmune encephalitis	Laboratory Neurology Psychiatry
anti-P1	anti-P1 antibody	Common cold-reacting antibody	Laboratory Hematology & Oncology
anti-PLA2R	anti-phospholipase A2 receptor antibody	Antibody linked to membranous kidney disease	Laboratory Renal & Nephrology
Anti-RNP	anti-ribonucleoprotein antibody	Autoimmune antibody linked to mixed connective tissue disease	Laboratory
Anti-Ro	anti-Ro/SSA antibody	Autoimmune antibody linked to Sjogren's and lupus	Laboratory Musculoskeletal
anti-S	anti-S antibody	MNS system red cell antibody	Laboratory Hematology & Oncology
Anti-Scl-70	anti-topoisomerase I antibody	Autoimmune antibody linked to systemic sclerosis	Laboratory Musculoskeletal
anti-Sm	anti-Smith antibody	Highly specific lupus antibody	Laboratory
anti-SMA	anti-smooth muscle antibody	Autoimmune hepatitis antibody	Laboratory Gastroenterology
Anti-Smith	anti-Smith antibody	Autoimmune antibody strongly linked to lupus	Laboratory
anti-Tg	anti-thyroglobulin antibody	Antibody against a thyroid protein	Laboratory Endocrinology
Anti-TPO	thyroid peroxidase antibody	Antibody found in autoimmune thyroid disease	Endocrinology Laboratory
Anti-tTG	tissue transglutaminase antibody	Blood antibody test for coeliac disease	Gastroenterology Laboratory
anti-VEGF	anti-vascular endothelial growth factor	Injected eye drug class blocking abnormal blood vessels	Prescription & Medication Orders General Medical
anti-Vel	anti-Vel antibody	Rare but hemolytic red cell antibody	Laboratory Hematology & Oncology
Anti-Xa	anti-factor Xa level	Blood test measuring heparin-type medicine effect	Laboratory Hematology & Oncology
anticipatory guidance	anticipatory guidance (counseling term)	Age-based safety and development counseling	Pediatrics Nursing
anticipatory guidance topics	anticipatory guidance (topic set)	Counseling topics by age	Pediatrics Nursing
ANUG	acute necrotizing ulcerative gingivitis	Painful destructive gum infection	General Medical Infectious Disease
Ao	aorta	Main artery carrying blood from the heart to the body	Cardiology
Ao arch	aortic arch (anatomy)	Curved top segment of the aorta	Cardiology Radiology & Imaging
AO/OTA	AO Foundation Orthopaedic Trauma Association classification	Standard fracture classification system	Musculoskeletal Surgery Radiology & Imaging
AOM	acute otitis media	Sudden infection of the middle ear	General Medical Infectious Disease Pediatrics
AP	acute pancreatitis	Sudden inflammation of the pancreas	Gastroenterology Emergency & Critical Care
AP view	anteroposterior view	X-ray taken front to back	Radiology & Imaging
APA	apalutamide (chart shorthand)	Prostate cancer hormone pill shorthand	Prescription & Medication Orders Hematology & Oncology
APACHE	Acute Physiology and Chronic Health Evaluation	Severity score used in intensive care	Emergency & Critical Care
APACHE pancreas	APACHE II in pancreatitis	General severity score applied to pancreatitis	Gastroenterology Emergency & Critical Care
APAP	acetaminophen	Paracetamol, a pain and fever medicine	Prescription & Medication Orders
APBI	accelerated partial breast irradiation	Shortened radiation to part of the breast	Hematology & Oncology Radiology & Imaging
APC	adenomatous polyposis coli gene	Gene mutated in familial colon polyps and cancer	Laboratory Hematology & Oncology Gastroenterology
aPCC	activated prothrombin complex concentrate	Bypassing agent for hemophilia with inhibitors	Hematology & Oncology Prescription & Medication Orders
APCR	activated protein C resistance	Inherited clotting tendency test, linked to factor V Leiden	Laboratory Hematology & Oncology
APD	afferent pupillary defect	Abnormal pupil response from optic nerve damage	General Medical Neurology
APD	automated peritoneal dialysis	Dialysis using a machine overnight at home	Renal & Nephrology
apex lung	lung apex (anatomy)	Top tip of the lung	Respiratory
APGAR	Appearance, Pulse, Grimace, Activity, Respiration	Newborn health score at one and five minutes	Obstetrics & Gynecology Pediatrics Vitals & Assessment
Apgar 1/5	Apgar scores at one and five minutes	Standard newborn score timings	Pediatrics Obstetrics & Gynecology Nursing
Apgar components	Apgar components (appearance pulse grimace activity respiration)	Five scored signs at birth	Pediatrics Obstetrics & Gynecology
APH	antepartum hemorrhage	Bleeding from the genital tract during pregnancy	Obstetrics & Gynecology Emergency & Critical Care
API	Asthma Predictive Index	Tool predicting asthma in wheezing toddlers	Pediatrics Respiratory
APL	abductor pollicis longus (muscle)	Thumb abducting muscle	Musculoskeletal
apnea prematurity	apnea of prematurity (diagnosis)	Breathing pauses of early birth	Pediatrics Respiratory
apnea test	apnea test (brain death)	Breathing test within brain death examination	Neurology Emergency & Critical Care
ApoA1	apolipoprotein A1	Main protein of HDL cholesterol particles	Laboratory Cardiology
ApoB	apolipoprotein B	Protein counting artery-related cholesterol particles	Laboratory Cardiology
APOE	apolipoprotein E	Gene influencing cholesterol and Alzheimer's risk	Laboratory Neurology Cardiology
appearance MSE	appearance (mental status element)	Observed presentation in the mental status exam	Psychiatry
apple peel	apple peel atresia (bowel)	Spiral bowel deformity with atresia	Pediatrics Gastroenterology Surgery
Appy	appendicectomy	Operation to remove the appendix	Gastroenterology Surgery
APRI	AST to platelet ratio index	Blood-based score estimating liver scarring	Gastroenterology Laboratory
APRN	advanced practice registered nurse	Nurse with advanced graduate-level training	Nursing
APRV	airway pressure release ventilation	Ventilator mode using long high-pressure phases with brief releases	Respiratory
APS	antiphospholipid syndrome	Autoimmune condition causing clots and pregnancy complications	Hematology & Oncology Obstetrics & Gynecology
aPTT	activated partial thromboplastin time	Blood clotting test used to monitor heparin effect	Laboratory Hematology & Oncology
AQP4	AQP4 antibody (neuromyelitis)	Water-channel antibody of NMOSD	Neurology Laboratory
AQP4	aquaporin-4 antibody	Antibody causing neuromyelitis optica	Laboratory Neurology
AQP4-IgG	aquaporin-4 immunoglobulin G	Antibody defining neuromyelitis optica spectrum disorder	Laboratory Neurology
aquablation	aquablation therapy (prostate)	Water-jet prostate tissue removal	Surgery Renal & Nephrology
aqueduct	cerebral aqueduct (anatomy)	Narrow channel connecting the ventricles	Neurology
AR	allergic rhinitis (nose)	Allergy-driven nasal inflammation — nose	General Medical Respiratory
AR	aortic regurgitation	Leaking of the aortic valve back into the heart	Cardiology
Ara-C	cytarabine	Core leukemia chemotherapy drug	Prescription & Medication Orders Hematology & Oncology
ARAT	Action Research Arm Test	Arm function test after stroke	Neurology Musculoskeletal
ARB	angiotensin receptor blocker	Blood pressure medicine blocking an artery-tightening hormone	Cardiology
ARBD	alcohol-related brain damage	Umbrella term for alcohol brain injury	Psychiatry Neurology
arcuate line	arcuate line (abdominal wall)	Lower border of the rectus sheath's back layer	Surgery
ARD	as regular diet (advance to regular)	Progression back to a normal diet	Nursing
ARDS	acute respiratory distress syndrome	Severe lung inflammation causing dangerous low oxygen levels	Respiratory Emergency & Critical Care
area puncture	area cannulation (technique caution)	Clustering needles in one patch, discouraged technique	Renal & Nephrology Nursing
ARF	acute respiratory failure	Sudden failure of breathing or gas exchange	Respiratory Emergency & Critical Care
ARFID	avoidant/restrictive food intake disorder	Eating disorder with avoidance of food without body image concerns	Psychiatry Pediatrics
Argyll Robertson	Argyll Robertson pupil	Pupil reacting to near but not light, classically syphilis	Neurology Infectious Disease
arm elevation test	arm elevation test (access outflow)	Fistula collapse check for outflow narrowing	Renal & Nephrology
ARMD	age-related macular degeneration	Eye disease damaging central vision in older people	General Medical
ARNI	angiotensin receptor-neprilysin inhibitor	Heart failure medicine combining two hormone-blocking actions	Cardiology
AROM	active range of motion	Joint movement a person performs by themselves	Musculoskeletal
AROM	artificial rupture of membranes	Deliberate breaking of the amniotic sac during care	Obstetrics & Gynecology
AROM against gravity	active range of motion against gravity	Movement strength grade descriptor	Musculoskeletal Neurology
AROM procedure	artificial rupture of membranes (procedure)	Breaking the waters with a hook — procedure	Obstetrics & Gynecology Nursing
ARPI	androgen receptor pathway inhibitor	Prostate cancer hormone pill class	Prescription & Medication Orders Hematology & Oncology
ARPKD	autosomal recessive polycystic kidney disease	Inherited kidney disease presenting in infancy or childhood	Pediatrics Renal & Nephrology
ARR	aldosterone-to-renin ratio	Ratio used when screening for primary aldosteronism	Laboratory Endocrinology Cardiology
ARS	acute rhinosinusitis	Short-term sinus inflammation	General Medical Infectious Disease
ART	antiretroviral therapy	Combination medicines suppressing HIV	Prescription & Medication Orders Infectious Disease
ART	assisted reproductive technology	Fertility treatments that handle eggs or embryos	Obstetrics & Gynecology
Art line	arterial line	Catheter in an artery monitoring blood pressure	Emergency & Critical Care Nursing
arteriolar hyalinosis	arteriolar hyalinosis (CNI lesion)	Small vessel change of CNI injury in biopsies	Renal & Nephrology Laboratory
arthrodesis	arthrodesis (joint fusion procedure)	Surgically fusing a joint	Surgery Musculoskeletal
ARVC	arrhythmogenic right ventricular cardiomyopathy	Heart muscle condition causing rhythm problems	Cardiology
AS	ankylosing spondylitis	Inflammatory disease mainly affecting the spine	Musculoskeletal
AS	aortic stenosis	Narrowing of the valve between the heart and the aorta	Cardiology
AS ⚠ Error-prone	left ear	The left ear, from Latin auris sinistra	General Medical
ASA	acetylsalicylic acid	Aspirin; a medicine that reduces clotting and pain	Cardiology
ASA	American Society of Anesthesiologists score	Grade of a patient's fitness before anesthesia	Surgery
ASA class	American Society of Anesthesiologists physical status	Anesthesia fitness classification	Surgery Vitals & Assessment
ASAP order	as soon as possible (order priority)	Urgent but not immediate order priority	Nursing General Medical
asc Ao	ascending aorta	First segment of the aorta leaving the heart	Cardiology Radiology & Imaging
ASC-US	atypical squamous cells of undetermined significance	Cervical screening result with cell changes of unclear significance	Obstetrics & Gynecology Laboratory
ASCO	ASCO classification (stroke)	Graded stroke cause classification	Neurology
ASD	acute stress disorder	Short-term stress reaction in the month after trauma	Psychiatry
ASD	atrial septal defect	Hole in the wall between the upper heart chambers	Cardiology Pediatrics
ASD	autism spectrum disorder	Developmental condition affecting communication and social interaction	Psychiatry Pediatrics
ASD trauma	acute stress disorder (trauma)	Early trauma reaction within a month	Psychiatry Emergency & Critical Care
ASES	American Shoulder and Elbow Surgeons score	Shoulder outcome questionnaire	Musculoskeletal
ash leaf	ash leaf spots (tuberous sclerosis)	Pale leaf-shaped skin spots	Pediatrics Neurology
ASL	arterial spin labeling	MRI perfusion method using labeled blood, no contrast	Radiology & Imaging Neurology
ASMA	smooth muscle antibody	Antibody seen in autoimmune hepatitis	Laboratory Gastroenterology
ASO	antistreptolysin O	Antibody showing recent streptococcus infection	Laboratory Infectious Disease Musculoskeletal
ASO titer	antistreptolysin O titer	Blood level showing recent strep infection	Laboratory Infectious Disease
ASPD	antisocial personality disorder	Personality pattern disregarding the rights of others	Psychiatry
ASPECTS	Alberta Stroke Program Early CT Score	CT score estimating early stroke change	Neurology Radiology & Imaging
Aspen	Aspen collar (brand-generic)	Common rigid neck collar type	Musculoskeletal Emergency & Critical Care
aspiration cath stroke	aspiration catheter (stroke device)	Vacuum catheter removing a brain clot	Neurology Radiology & Imaging
aspiration precautions	aspiration precautions (order)	Positioning and supervision preventing food entering the airway	Nursing Neurology
aspiration thromb	direct aspiration thrombectomy	Vacuum catheter removal of a clot	Neurology Radiology & Imaging Emergency & Critical Care
ASQ	Ages and Stages Questionnaire	Child development screening questionnaire	Pediatrics
ASQ-3	Ages and Stages Questionnaires-3	Developmental screening questionnaire edition	Pediatrics
ASRS	Adult ADHD Self-Report Scale (screen)	Adult ADHD screen — screening	Psychiatry
ASSR	auditory steady-state response	Frequency-specific hearing threshold test	Neurology Pediatrics
AST	aspartate aminotransferase	Liver and muscle enzyme measured in blood	Laboratory Gastroenterology
asterixis	asterixis (finding)	Flapping lapse of posture — finding	Neurology Gastroenterology
asthma action plan	asthma action plan (document)	Written zone-based asthma instructions	Pediatrics Respiratory Nursing
asthma child	childhood asthma (management)	Wheeze disease of childhood — management	Pediatrics Respiratory
astigmatism	astigmatism (corneal curve)	Uneven focusing	Pediatrics
AstV	astrovirus	Diarrhea-causing virus	Infectious Disease Gastroenterology Laboratory
ASV	adaptive servo-ventilation	Breathing machine adapting support to breathing pattern	Respiratory
asymmetric folds	asymmetric thigh folds (soft sign)	Uneven creases, a weak hip dysplasia clue	Pediatrics Musculoskeletal
asymmetric IUGR	asymmetric growth restriction	Growth restriction sparing the head	Obstetrics & Gynecology
ATA	anterior tibial artery	Front lower-leg artery	General Medical Musculoskeletal
ataxia telang	ataxia telangiectasia (genetic)	Balance disorder with immune deficiency	Pediatrics Neurology Infectious Disease
ataxic CP	ataxic cerebral palsy (type)	Unsteady-movement cerebral palsy type	Pediatrics Neurology
ATEZO	atezolizumab (chart shorthand)	PD-L1 immune checkpoint drug shorthand	Prescription & Medication Orders Hematology & Oncology
ATFL	anterior talofibular ligament	Ankle ligament most commonly injured in sprains	Musculoskeletal
ATG	antithymocyte globulin (induction)	T-cell depleting induction drug	Renal & Nephrology Prescription & Medication Orders Surgery Infectious Disease
athetosis	athetosis (movement)	Slow writhing movements	Neurology
ATIII	antithrombin III	Natural clot-preventing protein measured in clotting disorders	Laboratory Hematology & Oncology
ATL	anterior temporal lobectomy	Epilepsy operation removing the temporal lobe front	Surgery Neurology
Atlanta	revised Atlanta classification	Standard pancreatitis severity classification	Gastroenterology
atlantoaxial	atlantoaxial instability (Down)	Neck joint looseness screening in Down syndrome	Pediatrics Musculoskeletal Neurology
ATLS	Advanced Trauma Life Support	Standardised system for assessing injured patients	Emergency & Critical Care Surgery
ATM	ataxia-telangiectasia mutated gene	DNA repair gene in cancer risk testing	Laboratory Hematology & Oncology
ATN	acute tubular necrosis	Kidney injury from death of tubule cells	Renal & Nephrology
ATN	amyloid tau neurodegeneration (framework)	Alzheimer research classification framework	Neurology Laboratory
ATN transplant	acute tubular necrosis (graft)	Storage injury delaying graft function — graft	Renal & Nephrology Surgery Laboratory
ATNR	asymmetric tonic neck reflex	Fencing posture reflex of infants	Pediatrics Neurology
ATO	arsenic trioxide	Leukemia drug used with ATRA	Prescription & Medication Orders Hematology & Oncology
atonic seizure	atonic seizure (drop attack)	Sudden loss of muscle tone seizure	Neurology Pediatrics
atopic march	atopic march (progression)	Eczema to food allergy to asthma progression	Pediatrics Infectious Disease Respiratory
ATRA	all-trans retinoic acid	Differentiation drug for a type of acute leukemia	Prescription & Medication Orders Hematology & Oncology
ATRIA	ATRIA bleeding score	Bleeding risk score in atrial fibrillation	Cardiology
atropine penalization	atropine penalization (amblyopia)	Drops blurring the stronger eye	Pediatrics Prescription & Medication Orders
ATS/IDSA criteria	ATS/IDSA severe CAP criteria	Major and minor criteria for severe pneumonia	Respiratory Infectious Disease Emergency & Critical Care
ATTR	transthyretin amyloidosis	Protein deposit disease affecting heart and nerves	Cardiology Neurology
ATV safety	ATV injury prevention (guidance)	All-terrain vehicle safety guidance	Pediatrics Emergency & Critical Care
atypical absence	atypical absence seizure (type)	Slower staring seizure in developmental epilepsies	Neurology Pediatrics
atypical features	atypical features (specifier)	Depression specifier with mood reactivity and increased sleep	Psychiatry
AU ⚠ Error-prone	both ears	Both ears, from Latin auris utraque	General Medical
AUB	abnormal uterine bleeding	Bleeding from the uterus that is abnormal in amount, timing or frequency	Obstetrics & Gynecology
AUD	alcohol use disorder	Problematic pattern of alcohol use	Psychiatry
AUDIT	Alcohol Use Disorders Identification Test	Questionnaire screening for harmful alcohol use	Psychiatry General Medical
AUDIT-C	AUDIT-C (consumption screen)	Short alcohol screen — screening	Psychiatry
Augmentin	co-amoxiclav	Combination penicillin antibiotic, brand name Augmentin	Prescription & Medication Orders Infectious Disease
AUS	artificial urinary sphincter	Implanted continence device for men	Surgery Renal & Nephrology
autism screening	autism-specific screening (18/24 month)	Toddler autism checks at set ages	Pediatrics Psychiatry
auto-HSCT	autologous hematopoietic stem cell transplant	Transplant using the patient's own stem cells	Hematology & Oncology
auto-PEEP	auto-PEEP (intrinsic PEEP)	Trapped pressure from incomplete emptying	Respiratory Emergency & Critical Care
autonomic testing	autonomic testing (battery)	Sweat, heart and blood pressure reflex testing	Neurology
Auvi-Q	Auvi-Q (talking auto-injector brand)	Voice-guided adrenaline injector brand	Pediatrics Prescription & Medication Orders
AV	atrioventricular	Relating to the area between the upper and lower heart chambers	Cardiology
AV canal	atrioventricular canal defect (complete)	Combined hole and valve defect of the heart center	Pediatrics Cardiology
AV node	atrioventricular node	Electrical relay between the heart's upper and lower chambers	Cardiology
AVB	atrioventricular block	Delayed or blocked signal between upper and lower heart chambers	Cardiology
AVF	arteriovenous fistula	Surgically joined artery and vein for dialysis access	Renal & Nephrology Surgery
AVF creation	arteriovenous fistula creation	Joining an artery and vein for dialysis access	Surgery Renal & Nephrology
AVG	arteriovenous graft	Synthetic tube joining artery and vein for dialysis access	Renal & Nephrology Surgery
AVG creation	arteriovenous graft creation	Synthetic tube access for dialysis	Surgery Renal & Nephrology
AVM	arteriovenous malformation	Tangled cluster of abnormal blood vessels	Neurology
AVN	avascular necrosis	Bone death from loss of blood supply	Musculoskeletal
AVP	arginine vasopressin	Hormone controlling water balance, also called ADH	Laboratory Endocrinology Renal & Nephrology
AvPD	avoidant personality disorder	Personality pattern of social inhibition and fear of rejection	Psychiatry
AVPU	alert voice pain unresponsive (scale)	Simple consciousness scale — scale	Neurology Emergency & Critical Care Nursing
AVR	aortic valve replacement	Surgery to replace the aortic valve	Cardiology Surgery
AVSD	atrioventricular septal defect	Hole in the center of the heart involving both septa	Cardiology Pediatrics
awake intubation	awake intubation (technique)	Tube placement with numbing while the patient breathes	Emergency & Critical Care Respiratory Surgery
AWOL	absent without leave (patient)	Patient missing from a psychiatric or care unit	Nursing Psychiatry
AWS	alcohol withdrawal syndrome	Symptoms occurring when heavy drinking stops suddenly	Psychiatry
axillary art	axillary artery	Artery through the armpit	General Medical Musculoskeletal
axillary n	axillary nerve (anatomy)	Nerve to the shoulder cap muscle	Neurology Musculoskeletal
AXL	axial length	Eye length measured before cataract surgery	General Medical Surgery
AXR	abdominal X-ray	Imaging of the abdomen with X-rays	Radiology & Imaging Gastroenterology
axSpA	axial spondyloarthritis	Inflammatory arthritis mainly affecting spine and sacroiliac joints	Musculoskeletal
AZA	azathioprine	Immune-suppressing medicine used in several conditions	Prescription & Medication Orders
AZM	azithromycin (chart shorthand)	Macrolide antibiotic chart shorthand	Prescription & Medication Orders Infectious Disease

Educational reference only. This guide is for learning and quick reference. Abbreviations vary between hospitals, countries and specialties, and some are discouraged because they can be misread. Always write and interpret orders using your own institution’s approved abbreviation list, and check anything unclear with the prescriber or your local policy.

Medical Abbreviations Starting With "A"

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