Online Medical Dictionary

Letter U

Refers to a wide variety of mucous erosions, usually involving acidity. These include mouth ulcer (commonly referred to as canker sore), peptic ulcer of the stomach, corneal ulcer of the cornea, genital ulcer of the penis or vulva (usually associated with a sexually transmitted infection), and venous ulcer most often of the legs.
Cyclic sound waves, inaudible to the human ear, which can be used to monitor energy and create an image, such as in a sonography, used to create an image, or sonogram, of a fetus in utero.
Undifferentiated Cells
Cells which have failed to differentiate, or mature, thus defined as primitive. Undifferentiated cancers develop from malignant undifferentiated cells.
Composed of one cell.
Universal Donor
An individual with type O Rh D negative blood is said to be a universal donor, as this blood type can usually be accepted in individuals with any blood type available in the ABO blood typing system, with some conditional exceptions. Likewise, a universal recipient is defined as an individual with AB Rh D positive blood, as this blood type can usually accept donation from any ABO combination blood type, with some conditional exceptions.
Not able to be removed by surgical operation, such as in a malignant unresectable tumour.
See Uric Acid.
The bodily tube through which urine passes from the kidney to the bladder.
Inflammation of the urethra, most commonly caused by sexually transmitted infection (STI) such as Herpes simplex, gonorrhea, or chlamydia, but may also occur due other non-infectious syndrome or cause. Urethritis can induce difficult or painful urination (dysuria).
Uric Acid
The compound created when the body breaks down purine nucleotides. When the body accumulates a buildup of uric acid, or urate, hyperuricemia may develop, enabling urate crystals not disposed by the kidney to become lodged in joints, as is seen in the condition of gout. These joints may become inflamed and induce pain.
Urinary Calculus
See Kidney Stones.
Urinary Incontinence
The inability to control the passing of urine from the bladder.
Urinary Tract Infection
An infection of any element of the urinary tract, induced by bacteria, most frequently Escherichia coli. Urinary tract infections (UTIs) may prompt dysuria (difficult and painful urination), cloudy urine stream, and the frequent need to urinate with little or no result. UTIs can be treated with a course of antibiotics. Left untreated, bacteria may travel from the bladder into the kidneys and induce more serious infection.
A physician specialized in the diagnostics, treatment and management of conditions and diseases of the urinary tract. Organs composing the urinary tract include the urethra, ureter, bladder, kidneys and adrenal glands. In men, the urinary tract also includes the testes, prostate and penis.
Uterine Bleeding
Vaginal bleeding, induced normally by regular menstruation, but may also indicate an abnormal condition of the reproductive system. Uterine bleeding that occurs during pregnancy should be brought to the notice of a physician. Uterine bleeding may be confused with urinary tract bleeding, which may occur as a result of UTI or bladder infection. Vaginal bleeding may indicate a hormonal imbalance, uterine fibroids (benign uterine tumours), endometritis (in women who have recently been pregnant or delivered), uterine cancer or cervical cancer.
Uterine Cancer
Any type of malignancy: sarcoma, cervical cancer or endometrial cancer that develop from the tissues of the uterus. Treatment and prognosis will depend on the cancerous development; hysterectomy may be performed to extricate malignant uterine tissues.
Uterine Fibroids
Also called fibromyoma, myoma or fibroma, uterine fibroids are benign tumours that develop in the uterus, usually in females amid adulthood. If the size of the fibroids become symptomatic, causing pain during intercourse or urination, or affecting the need to urinate, medication may be administered or hysterectomy may be performed.
Uterine Rupture
A tear in the uterus, usually occurring during delivery but may occur in the late stages of pregnancy. Uterine rupture must be treated immediately, or else endangers both the mother and child. A laparotomy must be performed, incising a path to the abdomen though which the child can be delivered by cesarean, the uterus be repaired, and fluids transfused.