Medical terms - Letter U (page 2) | MedicalVocabulary.org

Unconscious

1. Interruption of awareness of oneself and one's surroundings, lack of the ability to notice or respond to stimuli in the environment. A person may become unconscious due to oxygen deprivation, shock, central nervous…
Unconsciousness, temporary

A partial or complete loss of consciousness with interruption of awareness of oneself and ones surroundings. When the loss of consciousness is temporary and there is spontaneous recovery, it is referred to as syncope…
Under the weather

Colloquial expression for sick or ill as, for example, to be under the weather with the flu. The phrase 'under the weather' came from British sailing ships. When a sailor became ill he was confined below deck out of the…
Underload syndrome

Literally being 'bored sick.' Lack of stimulation in life (such as with an extremely dull job) can result in depression and health problems including headaches, fatigue and recurrent infection
Underventilation

See: Hypoventilation
Underwater weighing

A method for determining the lean body mass. This method weighs a person underwater and then calculates the lean body mass (muscle) and body fat. This method is one of the more accurate ones. However, it is generally…
Undifferentiated cancer

Cancer: A cancer in which the cells are very immature and 'primitive' and do not look like cells in the tissue from it arose. As a rule, an undifferentiated cancer is more malignant than a cancer of that type which is…
Undulant fever

An infectious disease due to the bacteria Brucella that characteristically causes rising and falling fevers, sweats, malaise, weakness, anorexia, headache, myalgia (muscle pain) and back pain. The disease is called…
Undulatant

Having a wavy border or form. Also, rising and falling like a wave. For example, the border of a wound may be undulant, as may the edge of a rash. And sound waves may also be undulant. The word 'undulant' comes from the…
Undulate

To have a wavy border or form. Also, to rise and fall like a wave. For example, the border of a wound may undulate, as may the edge of a rash. And sound waves may undulate. The word 'undulate' comes from the Latin…
UNESCO

Acronym for the United Nations Educational, Scientific, and Cultural Organization
Unguis incarnatus

Ingrown toenail
Unicellular

Consisting of one cell only. Some organisms, such as bacteria, are unicellular. Unicellular is in contrast to multicellular
Unicornuate

Having one horn or being horn-shaped. The uterus is normally unicornuate
Unilateral

Having, or relating to, one side. Unilateral is as opposed, for example, to bilateral (which means having, or relating to, two sides)
Uniparous

1) Having produced only one offspring. Also called primiparous. 2) Producing only one offspring at a time. See also multiparous.
Unique identifier reporting

In public health, a system that uses information such as the person's birth date and part of their identification number (in the U.S., the social security number) to create a unique code that is reported instead of a…
Unit, international (IU)

An international unit (IU) is an internationally accepted amount of a substance. This type of measure is used for the fat-soluble vitamins (such as vitamins A, D and E) and certain hormones, enzymes, and biologicals…
United Network for Organ Sharing (UNOS)

The nationwide umbrella for transplantation organ sharing in the U.S. UNOS states that it is 'a private, not-for-profit, membership corporation qualified as a charitable organization under section 501 (c)(3) of the IRC…
United States Pharmacopeia

Abbreviated USP. A publication, established in 1820, that contains legally recognized standards of identity, strength, quality, purity, packaging, and labeling for drug substances, dosage forms, and other therapeutic…
United States Public Health Service

The agency responsible for the public health of the American people. The Public Health Service (PHS) administers a number of critically important health agencies including the Food and Drug Administration (FDA), the…
Universal colitis

Ulcerative colitis that involves the entire colon (the large intestine). Ulcerative colitis itself is a relatively common disease involving inflammation of the large intestine (the colon). The cause is unknown. It is a…
Universal donor

A person who is type O in the ABO blood group system and can donate blood to all recipients
UNOS

Acronym for the United Network for Organ Sharing, the nationwide umbrella for transplantation organ sharing in the U.S. UNOS states that it is 'a private, not-for-profit, membership corporation qualified as a charitable…
Unresectable

Unable to be removed (resected) by surgery. To resect is to remove. At the time of diagnosis of esophageal cancer, many patients have unresectable tumors
Unresolved grief

Grief characterized by the extended duration of the symptoms, by interference of the grief symptoms with the normal functioning of the mourner, and/or by the intensity of the symptoms (for example, intense suicidal…
Unsaturated fat

A fat that is liquid at room temperature and comes from a plant such as olive, peanut, corn, cottonseed, sunflower, safflower, or soybean. Unsaturated fats tend to lower the level of cholesterol in the blood
Unstable diabetes

A type of diabetes when a person's blood glucose (sugar) level often swings quickly from high to low and from low to high. Also called 'brittle diabetes' or 'labile diabetes.
Unsteadiness

Loss of one's equilibrium in regard to the environment, often with a feeling of almost falling, or the result of bumping into things. There are many causes for unsteadiness, including problems in the cerebral or…
Unwell

Not well or in good health, ailing, sick, indisposed. For example, 'I am well-nigh choked with the sulfurous heat of the weather -- or I am unwell.' (1826, Journal of Sir Walter Scott) 'Unwell' is also a euphemism for…
Up-regulation

See: Upregulation
Upper GI series

Upper GI series: A series of x-rays of the esophagus, stomach, and small intestine (upper gastrointestinal, or GI, tract) that are taken after the patient drinks a barium solution. (Barium is a white, chalky substance…
Upper leg

The upper leg is the superior (top) segment of the leg: the part above the knee. As compared to the lower leg which boasts two bones (the tibia and the fibula), the upper leg has only one bone: the femur but a very…
Upper motor neuron

A neuron that starts in the motor cortex of the brain and terminates within the medulla (another part of the brain) or within the spinal cord. Damage to upper motor neurons can result in spasticity and exaggerated…
Upper respiratory infection

An infection of the upper part of the respiratory system which is above the lungs. An upper respiratory infection can be due to any number of viral or bacterial infections. These infections may affect the throat…
Upregulation

An increase in the number of receptors on the surface of target cells, making the cells more sensitive to a hormone or another agent. For example, there is an increase in uterine oxytocin receptors in the third…
Urachus

A canal connecting the bladder of the fetus with the allantois, a structure that contributes to the formation of the umbilical cord. The lumen (inside) of the urachus is normally obliterated during embryonic…
Uracil (U)

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.
Uranium

A metallic element that is used as nuclear fuel and is highly toxic and radioactive. Exposure to radiation from uranium can occur in various ways. The breakdown of uranium products creates radon daughters. These can…
Urate

A salt derived from uric acid. When the body cannot metabolize uric acid properly, urates can build up in body tissues or crystallize within the joints. See also gout, uric acid.
Urban typhus of Malaya

Murine typhus, an acute infectious disease with fever, headache, and rash, all quite similar to, but milder than, epidemic typhus. It is caused by a related microorganism, Rickettsia typhi (R. mooseri), transmitted to…
Urea

A nitrogen-containing substance normally cleared from the blood by the kidney into the urine. Diseases that compromise the function of the kidney often lead to increased blood levels of urea, as measured by the blood…
Urea breath test (UBT)

The urea breath test (UBT) is a procedure for diagnosing the presence of a bacterium, Helicobacter pylori (H. pylori) that causes inflammation, ulcers, and atrophy of the stomach. The test also may be used to…
Ureaplasma

A bacterium that commonly infects the urogenital tract and can cause premature birth or spontaneous abortion. During delivery, ureaplasma can infect the newborn and cause meningitis, pneumonia, or septicemia. Ureaplasma…
Uremia

The presence of excessive amounts of urea in the blood, which may be a sign of kidney disease or failure. See also urea.
Ureter

A tube that carries urine down from the kidney to the bladder. There are normally two kidneys so there are accordingly two ureters under normal circumstances, one ureter coming from each kidney conveying urine to the…
Urethra

The transport tube leading from the bladder to discharge urine outside the body. In males, the urethra travels through the penis, and carries semen as well as urine. In females, the urethra is shorter than in the male…
Urethral meatus, female

The urethra is the transport tube leading from the bladder to discharge urine outside the body. In females the urethra is shorter than in the male. The meatus (opening) of the female urethra is above the vaginal…
Urethral opening, female

The urethra is the transport tube leading from the bladder to discharge urine outside the body. In females the urethra is shorter than in the male and opens above the vaginal opening, as indicated here: NTER>
Urethral sphincter

>Internal sphincter: Part of the muscular bladder wall acts as the internal urethral sphincter and prevents urine from leaving the bladder to enter the urethra. This sphincter cannot be willfully controlled but is under…