Medical terms A–Z

A substance that contains the element selenium (a nutrient that protects cells against damage) and is found in certain plants such as garlic and broccoli.

Sebum is an oily substance made by skin glands that lubricates and waterproofs skin and hair.

Refers to a new primary cancer in a person with a history of cancer.

Surgery performed after primary treatment to determine whether tumor cells remain.

A term that is used to describe either a new primary cancer or cancer that has spread from the place in which it started to other parts of the body.

Secondhand smoke combines exhaled and burning tobacco smoke, inhaled involuntarily by nonsmokers who share the same air.

To form and release a substance.

A hormone released into the blood by cells in the inner layer of the small intestine.

A drug used to help diagnose gastrinomas (tumors that cause too much gastric acid to be made) and other problems with the pancreas.

A test used to help diagnose problems in the pancreas, such as gastrinomas and pancreatitis.

A sedative reduces central nervous system activity to calm anxiety, ease agitation, or promote sleep, with effects ranging from mild relaxation to deep sedation.

The falling red cells are only a stand-in; what the test really tracks is a shift in the proteins dissolved around them.

A substance being studied in the treatment of some types of cancer.

Surgery to remove part of the bladder (the organ that holds urine).

The removal of cancer as well as some of the breast tissue around the tumor and the lining over the chest muscles below the tumor.

Surgery to remove part of an organ or gland.

Removal of one anatomical unit of an organ along its own blood supply, so the cut runs where nature already divided it.

Most seizures stop by themselves within a couple of minutes, and the confusion that follows often lasts considerably longer than the event.

An error in choosing the individuals or groups to take part in a study.

A drug that acts like estrogen on some tissues but blocks the effect of estrogen on other tissues.