top of page

Glossaries - N

We've defined thousands of terms related to health care. This page discusses glossary terms with the letter N.

Nausea (NAW-zee-uh)

The feeling of wanting to throw up (vomit).

Necrosis (neck-KROH-sis)

Dead tissue that surrounds healthy tissue in the body.

Necrotizing Enterocolitis (NEK-roh-TY-zing EN-tuh-roh-koh-LY-tis)

A condition in which part of the tissue in the intestines is destroyed. Occurs mainly in under-weight newborn babies. A temporary ileostomy may be necessary.

Neonatal Hepatitis (nee-oh-NAY-tul heh-puh-TY-tis)

Irritation of the liver with no known cause. Occurs in newborn babies. Symptoms include jaundice and liver cell changes.

Neoplasm (NEE-oh-plaz-um)

New and abnormal growth of tissue that may or may not cause cancer. Also called tumor.

Nissen Fundoplication (NIH-sun FUN-doh-plih-KAY-shun)

An operation to sew the top of the stomach (fundus) around the esophagus. Used to stop stomach contents from flowing back into the esophagus (reflux) and to repair a hiatal hernia.

Neuron (NUR-on)

a nerve cell.


Disease of the nervous system. Many people who have had diabetes for a while have nerve damage. The three major forms of nerve damage are: peripheral neuropathy, autonomic neuropathy, and mononeuropathy. The most common form is peripheral neuropathy, which mainly affects the feet and legs. See also: Peripheral neuropathy.

Neutralizing antibody

an antibody that keeps a virus from infecting a cell, usually by blocking receptors on the cells or the virus.

Neutropenia (new-tro-PEE-knee-ah)

a decrease in the number of white blood cells.

NK cell (natural killer cell)

a non-specific lymphocyte. NK cells, like killer T cells, attack and kill cancer cells and cells infected by microorganisms. NK cells are "natural" killers because they do not need to recognize a specific antigen in order to attack and kill.

Noninsulin-dependent Diabetes Mellitus (NIDDM)

The most common form of diabetes mellitus; about 90 to 95 percent of people who have diabetes have NIDDM. Unlike the insulin-dependent type of diabetes, in which the pancreas makes no insulin, people with noninsulin- dependent diabetes produce some insulin, sometimes even large amounts. However, either their bodies do not produce enough insulin or their body cells are resistant to the action of insulin (see Insulin Resistance). People with NIDDM can often control their condition by losing weight through diet and exercise. If not, they may need to combine insulin or a pill with diet and exercise. Generally, NIDDM occurs in people who are over age 40. Most of the people who have this type of diabetes are overweight. Noninsulin-dependent diabetes mellitus used to be called "adult-onset diabetes," "maturity-onset diabetes," "ketosis-resistant diabetes," and "stable diabetes." It is also called type II diabetes mellitus.

Nonsteroidal anti-inflammatory drugs (NSAIDs)

A group of medications, including aspirin, ibuprofen, and related drugs, used to reduce inflammation that causes joint pain, stiffness, and swelling.

Nontropical Sprue (NAWN-TRAH-pih-kul SPROO)

Nonulcer Dyspepsia (nawn-UL-sur dis-PEP-see-uh)

Constant pain or discomfort in the upper GI tract. Symptoms include burning, nausea, and bloating, but no ulcer. Possibly caused by muscle spasms.


a component molecule of RNA and DNA.


the central controlling body within a living cell, usually a spherical unit enclosed in a membrane and containing genetic codes for maintaining life systems of the organism and for issuing commands for growth and reproduction.

Nutcracker Syndrome (NUT-KRAK-ur sin-drohm)

Abnormal muscle tightening in the esophagus.

bottom of page