Rickets is the softening and weakening of bones in children, usually because of an extreme and prolonged vitamin D deficiency. Vitamin D promotes the absorption of calcium and phosphorus from the gastrointestinal tract. A deficiency of vitamin D makes it difficult to maintain proper calcium and phosphorus levels in bones, which can cause rickets. Adding vitamin D or calcium to the diet generally corrects the bone problems associated with rickets. When rickets are due to another underlying medical problem, your child may need additional medications or other treatment. Some skeletal deformities caused by rickets may require corrective surgery.

Hold your elbows at shoulder level and place the backs of your hands together with your wrists bent at 90 degrees. This position increases the pressure on the median nerve. If the test reproduces or worsens your symptoms (pain and tingling in your hands), you may have carpal tunnel syndrome.

Transvenous cardiac pace maker, also called endocardial pacing, is a potentially life saving intervention used primarily to correct profound bradycardia. It can be used to treat symptomatic bradycardias that do not respond to transcutaneous pacing or to drug therapy.

Scleroderma (skleer-oh-DUR-muh) is a group of rare diseases that involve the hardening and tightening of the skin and connective tissues — the fibers that provide the framework and support for your body. In some people, scleroderma affects only the skin. But in many people, scleroderma also harms structures beyond the skin — such as blood vessels, internal organs and the digestive tract. Signs and symptoms vary, depending on which structures are affected. Scleroderma affects women more often than men and most commonly occurs between the ages of 30 and 50. While there is no cure for scleroderma, a variety of treatments can ease symptoms and improve quality of life.

An enlarged spleen can be caused by infections, cirrhosis and other liver diseases, blood diseases characterized by abnormal blood cells, problems with the lymph system, or other conditions. Other causes of an enlarged spleen include: Inflammatory diseases such as sarcoidosis, lupus, and rheumatoid arthritis.

Systemic circulation carries oxygenated blood from the left ventricle, through the arteries, to the capillaries in the tissues of the body. From the tissue capillaries, the deoxygenated blood returns through a system of veins to the right atrium of the heart.

Colonoscopy is a test that allows your doctor to look at the inner lining of your large intestine (rectum and colon). He or she uses a thin, flexible tube called a colonoscope to look at the colon. A colonoscopy helps find ulcers, colon polyps, tumors, and areas of inflammation or bleeding.

A hiatus hernia or hiatal hernia is the protrusion (or herniation) of the upper part of the stomach into the thorax through the esophageal hiatus because of a tear or weakness in the diaphragm. Hiatus hernias often result in heartburn but may also cause chest pain or pain with eating. The most common cause is obesity.

In most instances, STDs are passed from an infected person to another person during sexual activities, through contact with the mucous membranes of the penis, vagina, mouth and rectum. Such activity includes vaginal, oral and anal intercourse. Gonorrhea and chlamydia also can be transmitted by fingers to eyes. A sexually transmissible infection (STI) is any infection or disease that can be passed from one person to another during sexual activity. Sexually transmissible infections include chlamydia, herpes, gonorrhoea, syphilis, genital herpes, scabies, pubic lice (crabs), hepatitis and HIV (the virus that causes AIDS).

Here we’ll explain the symptoms of pancreatitis, how alcohol causes the condition and the other health problems it can lead to. You probably don’t pay much attention to your pancreas. But that small, tadpole-shaped organ behind your stomach and below your ribcage is pretty important. It produces two essential substances: digestive juices which your intestines use to break down food, and hormones that are involved in digestion, such as insulin, which regulates your blood sugar levels. Pancreatitis is when your pancreas becomes inflamed and its cells are damaged. Heavy drinking can cause pancreatitis. But if you drink within the government’s low risk unit guidelines, you should avoid upsetting this important organ.

Although the Apgar score was developed in 1952 by an anesthesiologist named Virginia Apgar, you also might hear it referred to as an acronym for: Appearance, Pulse, Grimace, Activity, and Respiration. The Apgar test is usually given to a baby twice: once at 1 minute after birth, and again at 5 minutes after birth.

Nephritis and Nephrotic Syndrome

Endometriosis (en-doe-me-tree-O-sis) is an often painful disorder in which tissue that normally lines the inside of your uterus — the endometrium — grows outside your uterus. Endometriosis most commonly involves your ovaries, fallopian tubes and the tissue lining your pelvis. Rarely, endometrial tissue may spread beyond pelvic organs.

Pompe disease is a rare multisystem genetic disorder that is characterized by absence or deficiency of the lysosomal enzyme alpha-glucosidase (GAA). This enzyme is required to breakdown (metabolize) the complex carbohydrate glycogen and convert it into the simple sugar glucose.

A hemolytic transfusion reaction is a serious complication that can occur after a transfusion of blood. The red blood cells that were given in the transfusion are destroyed by the patient's immune system. There are other types of allergic transfusion reactions that do not cause hemolysis.

The "Get up and go" test is most commonly used to assess postural stability. In this test, the physician instructs the patient to stand up from a chair without assistance, walk a short distance, turn around, return, and sit down again. If the patient is unsteady or has difficulties during the test, further evaluation is necessary.

Holter monitoring, electrocardiogram or echocardiogram are only recommended if a cardiac cause (e.g., arrhythmias, possible cardiac syncope, myocardial ischemia) is suspected.

Device that keeps a donor heart beating

Atrial fibrillation vs Atrial Flutter

The National Institute of Allergy and Infectious Diseases explains food allergy and offers tips on how to manage the condition.