urethritis, infection and inflammation of the urethra, the channel for passage of urine from the urinary bladder to the outside. Urethritis is more frequent in males than in females.
The causes of urethritis vary with age, sexual practices, and hygienic standards. Urethritis due to fecal contamination or irritation due to physical trauma or chemical substances is common in young children. After puberty the most common known causes of the condition are Chlamydia and gonorrhea, which are spread through sexual intercourse. The cells of the mucous glands in the lining of the urethra serve as important harbouring places for the chlamydial and gonococcal bacteria, which invade the glands while the infection is just beginning and remain in them even after the mucous membrane has healed. Another common urethral infection is caused by the protozoan Trichomonas vaginalis, frequently resident in the vagina. Urethritis can also be caused by chemical irritants, by the spread of infection from other parts of the urinary tract, or by trauma, such as from the introduction of foreign bodies into the urethra.
The onset of urethritis is accompanied by the discharge of a yellow or green fluid. Inflammation in the urethra can cause progressive scarring that may narrow the channel, and swelling and the buildup of fibrous tissue can make urination difficult and painful. Obstruction or constriction of the urethra usually produce the same results: urination becomes difficult or impossible, causing an accumulation of stagnant urine in the bladder, and this usually leads to severe infection. If the infection is not treated, back pressure may prevent urine from leaving the kidneys, causing kidney failure.
Diagnosis of urethritis is established by taking a Gram stain and a culture of urethral discharges. Treatment may simply involve the withdrawal of the offending chemical agent, when the inflammation is caused by chemical irritation, or the administration of antibiotics, when microorganisms are involved. If it is suspected that the infection has spread to the bloodstream, the patient must be hospitalized and treated with intravenous antibiotics.