Urination
A. Difficult Urination (Dysuria). Difficulty in the voiding of urine may come from conditions involving the urethra, such as stricture following an old infection, or from pressure from outside the urethra as by an enlarged prostate. It can occur as a consequence of taking certain drugs.
Cystitis (inflammation of the lining of the bladder) may cause a spasm of the muscle that normally keeps the outlet of the bladder closed. Injuries or disease of the spinal cord or of the nerves that pass from the spinal cord to the bladder may prevent normal control of the muscles concerned with emptying the bladder. A tumor near the outlet of the bladder or stones within the bladder may obstruct the flow of urine temporarily or intermittently.
B. Excessive Urination (Polyuria). The amount of urine expelled from the bladder depends on how much fluid has been taken into the body and on how much of this has been eliminated by other means, by sweat and by loss from the digestive organs. In diabetes there is excessive elimination of water through the urine and a corresponding thirst and increase of water intake. Certain drugs alter the body's water balance by increasing the volume of urine.
C. Frequent Urination. The urge to urinate frequently is usually caused by irritation of the lining of the bladder, as in cystitis. This is usually the result of an infection and should be examined and treated by a physician. Bladder infection may be associated with infection of the kidneys, prostate, or urethra. The patient with cystitis usually experiences a burning sensation when urine is passed. With enlargement of the prostate, the bladder does not always empty completely. This retention of some residual urine favors infection of the bladder with a resulting frequency of urination. Also, when the bladder does not empty completely it naturally will fill up again sooner.
D. Scanty Urination (Oliguria). Urine becomes scanty if insufficient fluid is taken into the body or if there is a considerable loss of water through sweat (as in hot weather) or an unusual loss of water from the digestive organs (as in prolonged vomiting or diarrhea). In acute glomerulonephritis (kidney disease) the ability of the kidneys to eliminate water from the body is reduced, and fluid accumulates in the body's tissues. (See Edema: B. Edema in Kidney Disease.) Fluid may accumulate in the abdominal cavity. (See Abdomen B: Distension of the Abdomen.)
E. Uncontrolled Urination. (See Incontinence.)
