- Physical Examination
- Surgical Examination
- Ophthalmology
- Clinical Skills
- Orthopedics
- Surgery Videos
- Laparoscopy
- Pediatrics
- Funny Videos
- Cardiothoracic Surgery
- Nursing Videos
- Plastic Surgery
- Otorhinolaryngology
- Histology and Histopathology
- Neurosurgery
- Dermatology
- Pediatric Surgery
- Urology
- Dentistry
- Oncology and Cancers
- Anatomy Videos
- Health and Fitness
- Radiology
- Anaesthesia
- Physical Therapy
- Pharmacology
- Interventional Radiology
- Cardiology
- Endocrinology
- Gynecology
- Emergency Medicine
- Psychiatry and Psychology
- Childbirth Videos
- General Medical Videos
- Nephrology
- Physiology
- Diet and Food Health
- Diabetes Mellitus
- Neurology
- Women Health
- Osteoporosis
- Gastroenterology
- Pulmonology
- Hematology
- Rheumatology
- Toxicology
- Nuclear Medicine
- Infectious Diseases
- Vascular Disease
- Reproductive Health
- Burns and Wound Healing
- Kidney Zone Podcast
- Other
Total Thyroxine
Abbreviation: Total T4
Panel: Thyroid Tests · All thyroid tests
Typical adult reference range
| Conventional units | 5.0–12.0 µg/dL |
| SI units | 64–154 nmol/L |
Ranges vary between laboratories and methods — compare your result with the range printed on your own report.
What a high or low result can mean
High total thyroxine: high values can be seen in hyperthyroidism and with increased binding proteins, including in pregnancy.
Low total thyroxine: low values may occur in hypothyroidism and with reduced binding proteins.
These are associations, not a diagnosis: the same result can have several causes, and your clinician interprets it with the rest of your results and history.
Good to know
Affected by changes in thyroid hormone binding proteins.
Related tests — Thyroid Tests
Please note: Reference ranges vary between laboratories, and between the methods and instruments they use — the range printed on your own report is the one your result should be compared with. A result outside the range is not by itself a diagnosis, and a result inside it does not rule out illness. These pages are an educational summary, not medical advice: always discuss your results with the clinician who ordered them, who can interpret them in the context of your health and history.