A segment of DNA with an identifiable physical location on a chromosome and whose inheritance can be followed. A marker can be a gene, or it can be some section of DNA with no known… 

A type of immune reaction seen in some diseases in which the body encapsulates the offending substance.

A vaccination to prevent hepatitis B. The vaccine leads the body to make its own protection (antibodies) against the virus.

An acid made in the stomach that works with pepsin and other enzymes to break down proteins.

Dyspepsia.

A sign of many disorders. The skin and eyes turn yellow from too much bilirubin in the blood. See hyperbilirubinemia.

A cleaning of the stomach and colon that uses a special drink and enemas. See bowel prep.

A condition caused by not eating enough food or not eating a balanced diet.

A condition in which the muscle contraction in the esophagus is too strong, causing chest pain or difficulty swallowing.

The passage of an instrument through the skin to allow access to the organs.