Medical terms - Letter U | MedicalVocabulary.org

U (uracil)

A nucleotide base and one member of the A-U (adenine-uracil) base pair in RNA. The other base pair in RNA is G-C (guanine-cytosine). Uracil takes the place in RNA that thymine (T) occupies in DNA.
U.S. National Library of Medicine (NLM)

The world's largest medical library, the U.S. National Library of Medicine (NLM) is part of the National Institutes of Health (NIH). The NLM has as its mission to collect, organize, and make available biomedical science…
UA

Abbreviation for urinalysis, a test that determines the content of the urine. Because urine removes toxins and excess liquids from the body, it can contain important clues. Urinalysis can be used to detect some types of…
UAA

A triplet consisting of uracil, adenine, adenine, in that order, that acts as a stop codon in messenger RNA (mRNA), signaling the termination of translation of an mRNA molecule and the release of the nascent polypeptide…
UAG

A triplet consisting of uracil, adenine, guanine, in that order, that acts as a stop codon in messenger RNA (mRNA), signaling the termination of translation of an mRNA molecule and the release of the nascent polypeptide…
UAL

UAL stands for ultrasonic-assisted liposuction. Liposuction involves the surgical suctioning of fat deposits from specific parts of the body, the most common being the abdomen (the 'tummy'), buttocks ('behind'), hips…
Ubidecarenone

See: Coenzyme Q10
Ubiquinone

See: Coenzyme Q10
Ubiquitin

A small but extremely important protein that acts the 'kiss of death' to other proteins. Ubiquitin consists of only 76 amino acids. In the normal course of events, proteins are inactivated by the attachment of ubiquitin…
Ubiquitination

The 'kiss of death' process for a protein. In ubiquitination, a protein is inactivated by attaching ubiquitin to it. Ubiquitin is a small molecule. It acts as a tag that signals the protein-transport machinery to ferry…
Ubiquitous

Present everywhere. The small protein called ubiquitin was so-named because it is present in all types of cells and its amino acid sequence is identical in all creatures from insects to humans
UBT

Urea breath test
UDP-glucuronosyltransferase

A liver enzyme essential to the disposal of bilirubin (the chemical that results from the normal breakdown of hemoglobin from red blood cells). An abnormality of this enzyme (UDP-glucuronosyltransferase) results in a…
UGA

A triplet consisting of uracil,guanine, adenine, in that order, that acts as a stop codon in messenger RNA (mRNA), signaling the termination of translation of an mRNA molecule and the release of the nascent polypeptide…
UL

1. Upper lid (of the eye). 2. Upper limit. No evidence was found for chronic excess intakes of potassium in apparently health individuals and therefore no UL was established for potassium
Ulcer

An area of tissue erosion, for example, of the skin or lining of the gastrointestinal (GI) tract. Due to the erosion, an ulcer is concave. It is always depressed below the level of the surrounding tissue. Ulcers can…
Ulcer, aphthous

Ulcer, aphthous: A small sensitive painful ulcer crater in the lining of the mouth. Commonly called a canker sore. Aphthous ulcers are one of the most common problems that occur in the mouth. About 20% of the population…
Ulcer, Buruli

See: Buruli ulcer
Ulcer, duodenal

See: Duodenal ulcer
Ulcer, esophageal

A hole in the lining of the esophagus (tube-like organ leading from the throat to the stomach) corroded by the acidic digestive juices secreted by the stomach cells. Ulcer formation is related to H. pyloridus bacteria…
Ulcer, gastric

A hole in the lining of the stomach corroded by the acidic digestive juices which are secreted by the stomach cells. Ulcer formation is related to H. pyloridus bacteria in the stomach, anti-inflammatory medications, and…
Ulcer, peptic

A peptic ulcer is a hole in the lining of the stomach, duodenum, or esophagus. A peptic ulcer of the stomach is called a gastric ulcer, an ulcer of the duodenum is a duodenal ulcer, and a peptic ulcer of the esophagus…
Ulcer, stasis

A stasis ulcer is an ulcer (a crater) that develops in an area in which the circulation is sluggish and the venous return (the return of venous blood toward the heart) is poor. A common location for stasis ulcers is on…
Ulceration

The process or fact of being eroded away, as by an ulcer
Ulcerative colitis

Ulcerative colitis: A relatively common disease that causes inflammation of the large intestine (the colon). The cause is unknown. Ulcerative colitis is a form of inflammatory bowel disease. It has some similarity to a…
Ulcerative gingivitis

This is trench mouth, a progressive painful infection with ulceration, swelling and sloughing off of dead tissue from the mouth and throat due to the spread of infection from the gums. Certain germs (including fusiform…
Ulcerative proctitis

Ulcerative colitis that is limited to the rectum. Ulcerative colitis itself is a relatively common disease involving inflammation of the large intestine (the colon). The cause is unknown. It is a form of inflammatory…
Ullrich congenital muscular dystrophy

A disorder evident at birth characterized by muscle weakness, contractures of multiple joints, and hyperextensibility (looseness) of joints, particularly distal joints (well away from the trunk). The muscle weakness…
Ulna

The larger of the two long bones within the forearm. (The smaller one is the radius). The ulna is on the same side of the arm as the little finger
Ulnar

Referring to the larger of the two long bones in the forearm. (The smaller one is the radius). The ulna is on the same side of the arm as the little finger
Ulnar nerve

A major nerve in the upper extremity. The ulnar nerve begins in the lower cervical and upper thoracic portions of the spinal cord (from C7 to T1), travels via the brachial plexus down into the arm, through the cubital…
Ulocarcinoma

Cancer of the gums. It is often associated with the use of smokeless (chewing) tobacco. Diagnosis is by observation and confirmed by biopsy. Treatment may include radiation, chemotherapy, and surgery
Ultrafast CT

Electron beam computerized tomography (EBCT), a new (and controversial) noninvasive test for the detection of coronary artery disease (CAD). Ultrafast computerized tomography is designed to measure calcium deposits in…
Ultrasonic-assisted liposuction

Liposuction involves the surgical suctioning of fat deposits from specific parts of the body, the most common being the abdomen (the 'tummy'), buttocks ('behind'), hips, thighs and knees, chin, upper arms, back, and…
Ultrasound

Ultrasound: High-frequency sound waves. Ultrasound waves can be bounced off of tissues using special devices. The echoes are then converted into a picture called a sonogram. Ultrasound imaging, referred to as…
Ultrasound during pregnancy

Ultrasound imaging has been done during pregnancy for over three decades. It has proven to be a very useful and very effective diagnostic procedure. A number of epidemiological studies of pregnancy ultrasound exposure…
Ultrasound, Doppler

See: Doppler ultrasound
Ultrasound, endoscopic

See: Endoscopic ultrasound
Ultrasound, transvaginal

A technique in which sound waves are sent out by an ultrasound probe that has been inserted in the vagina. The waves go through the vaginal wall and bounce off the ovaries, and a computer uses the ultrasound echoes to…
Ultrasound/Ultrasonography

A test in which high-frequency sound waves (ultrasound) are bounced off tissues and the echoes are converted into a picture (sonogram).
Ultraviolet A

One of the three types of invisible light rays (together with ultraviolet B and ultraviolet C) given off by the sun. Although ultraviolet C is the most dangerous type of ultraviolet light in terms of its potential to…
Ultraviolet B

One of the three types of invisible light rays (together with ultraviolet A and ultraviolet C) given off by the sun. Although ultraviolet C is the most dangerous type of ultraviolet light in terms of its potential to…
Ultraviolet C

One of the three types of invisible light rays (together with ultraviolet A and ultraviolet B) given off by the sun. Although ultraviolet C is the most dangerous type of ultraviolet light in terms of its potential to…
Ultraviolet radiation

Invisible rays that are part of the energy that comes from the sun. Ultraviolet radiation can burn the skin and cause skin cancer. Ultraviolet radiation is made up of three types of rays -- ultraviolet A, ultraviolet B…
Umami

The taste of substances such as glutamate and monosodium glutamate (MSG) that are found in foods like bouillon and other stocks. Umami is the fifth primary element of taste. The other four are sweet, sour, salty, and…
Umbilical cord

The cord that connects the developing embryo or fetus with the placenta and through which run the umbilical arteries and vein. The matrix (the substance) of the umbilical cord is known as Wharton's jelly and is a rich…
Umbilicus

The vestige left behind on a newborn's belly when the umbilical cord is cut. Also called the navel or belly button
UMP

Uridine monophosphate
Unassisted childbirth

Birth of a baby without the assistance of an obstetrician, midwife, or other health professional. This may be by accident or by design. Unassisted childbirth is fraught with risks since about a fifth of apparently…
Uncertainty

You may be uncertain why 'uncertainty' deserves a place in a medical dictionary but some would say that uncertainty is a key element in medicine. 'The core predicament of medicine -- the thing that makes being a patient…