The immune system is the body's defense against infectious organisms and other invaders. Through a series of steps called the immune response, the immune system attacks organisms and substances that invade body systems and cause disease.

Headache is pain in any region of the head. Headaches may occur on one or both sides of the head, be isolated to a certain location, radiate across the head from one point, or have a viselike quality. A headache may appear as a sharp pain, a throbbing sensation or a dull ache. Headaches can develop gradually or suddenly, and may last from less than an hour to several days

Neck pain is a common complaint. Neck muscles can be strained from poor posture — whether it's leaning over your computer or hunching over your workbench. Osteoarthritis also is a common cause of neck pain. Rarely, neck pain can be a symptom of a more serious problem. Seek medical care if your neck pain is accompanied by numbness or loss of strength in your arms or hands or if you have shooting pain into your shoulder or down your arm

Chronic kidney disease includes conditions that damage your kidneys and decrease their ability to keep you healthy by doing the jobs listed. If kidney disease gets worse, wastes can build to high levels in your blood and make you feel sick. You may develop complications like high blood pressure, anemia (low blood count), weak bones, poor nutritional health and nerve damage. Also, kidney disease increases your risk of having heart and blood vessel disease. These problems may happen slowly over a long period of time. Chronic kidney disease may be caused by diabetes, high blood pressure and other disorders. Early detection and treatment can often keep chronic kidney disease from getting worse. When kidney disease progresses, it may eventually lead to kidney failure, which requires dialysis or a kidney transplant to maintain life.

MENTAL STATUS EXAMINATION

Cardiac arrest is the abrupt loss of heart function in a person who may or may not have diagnosed heart disease. The time and mode of death are unexpected. It occurs instantly or shortly after symptoms appear. Each year, more than 350,000 emergency medical services-assessed out-of-hospital cardiac arrests occur in the United States

You can decrease your risk of getting Lyme disease with some simple precautions: Cover up. ... Use insect repellents. ... Do your best to tick-proof your yard. ... Check yourself, your children and your pets for ticks. ... Don't assume you're immune. ... Remove a tick as soon as possible with tweezers.

Depression (major depressive disorder or clinical depression) is a common but serious mood disorder. It causes severe symptoms that affect how you feel, think, and handle daily activities, such as sleeping, eating, or working. To be diagnosed with depression, the symptoms must be present for at least two weeks.

Lead poisoning occurs when lead builds up in the body, often over a period of months or years. Even small amounts of lead can cause serious health problems. Children under the age of 6 are especially vulnerable to lead poisoning, which can severely affect mental and physical development. At very high levels, lead poisoning can be fatal. Lead-based paint and lead-contaminated dust in older buildings are the most common sources of lead poisoning in children. Other sources include contaminated air, water and soil. Adults who work with batteries, do home renovations or work in auto repair shops also may be exposed to lead. While treatment is available for lead poisoning, taking some simple precautions can help protect yourself and your family.

Initial symptoms may include: Pain or discomfort in the upper tummy (abdomen), especially after eating. Indigestion. (Note: most people who have indigestion do not have stomach cancer.) Feeling sick, and being off food. ... Weight loss and/or loss of appetite. You may pass blood out with your stools (faeces).

Ankylosing spondylitis is an inflammatory disease that, over time, can cause some of the vertebrae in your spine to fuse. This fusing makes the spine less flexible and can result in a hunched-forward posture. If ribs are affected, it can be difficult to breathe deeply. Ankylosing spondylitis affects men more often than women. Signs and symptoms typically begin in early adulthood. Inflammation also can occur in other parts of your body — most commonly, your eyes. There is no cure for ankylosing spondylitis, but treatments can lessen your symptoms and possibly slow progression of the disease.

Rotator cuff repair is surgery to repair a torn tendon in the shoulder. The procedure can be done with a large (open) incision or with shoulder arthroscopy, which uses small buttonhole-sized incisions.

This video: Sickle cell anemia is an inherited form of anemia which is a condition in which there aren't enough healthy red blood cells to carry adequate oxygen throughout your body. Normally, your red blood cells are flexible and round, moving easily through your blood vessels. In sickle cell anemia, the red blood cells become rigid and sticky and are shaped like sickles or crescent moons. These irregularly shaped cells can get stuck in small blood vessels, which can slow or block blood flow and oxygen to parts of the body. There's no cure for most people with sickle cell anemia. However, treatments can relieve pain and help prevent further problems associated with sickle cell anemia.

Are you getting enough vitamin B12? Many people don’t, and that deficiency can cause some serious problems. Vitamin B12 does a lot of things for your body. It helps make your DNA and your red blood cells, for examples. Since your body doesn't make vitamin B12, you'll need to get it from animal-based foods or from supplements, and it needs to be consumed on a regular basis. Exactly how much you need and where you should get it from depends on things like your age, the diet you follow, your medical conditions, and in some cases what medications you take.

Tension pneumothorax describes the progressive accumulation of air in the pleural cavity (normally a potential space) through a defect in the visceral pleura. This leads to positive pressure being maintained and increasing throughout the respiratory cycle causing vessels within the mediastinum to be compressed with catastrophic consequences if left untreated. Clinical signs include hypoxia, hypotension, tachycardia, reduced breath sounds and hyper resonance ipsilaterally, with tracheal deviation (away from the affected side) and distended neck veins being late clinical signs.

The best way to prevent hepatitis A is through vaccination with the hepatitis A vaccine. Vaccination is recommended for all children age 12 months or older, for travelers to certain countries, and for people at high risk for infection with the virus. The hepatitis A vaccine is given as two shots, six months apart.

The physical signs of pregnancy are easy to recognize -- nausea, fatigue, that swollen belly and (often) a healthy glow. But what if you had these telltale pregnancy symptoms -- and weren't actually pregnant? As crazy as it sounds, it does happen. False pregnancy, or pseudocyesis, is a condition in which a woman believes that she's pregnant, yet conception hasn't taken place and no baby is forming inside. Common, and often lasting, pregnancy symptoms help to reinforce this idea, which can lead a woman to be absolutely certain she's expecting, for months or even years!

Golfer's elbow causes pain that starts on the inside bump of the elbow, the medial epicondyle. Wrist flexors are the muscles of the forearm that pull the hand forward. The wrist flexors are on the palm side of the forearm. Most of the wrist flexors attach to one main tendon on the medial epicondyle.

A broken bone requires emergency medical care. Your child might have a broken (fractured) bone if he or she heard or felt a bone snap, has difficulty moving the injured part, or if the injured part moves in an unnatural way or is very painful to the touch. A sprain occurs when the ligaments, which hold bones together, are overstretched and partially torn. A strain is when a muscle or tendon is overstretched or torn. Sprains and strains generally cause swelling and pain, and there may be bruises around the injured area. Most sprains and strains, after proper medical evaluation, can be treated at home.

This tiny wireless pacemaker can be inserted into the body via a catheter instead of invasive surgery.