Stress incontinence occurs when the internal sphincter muscle surrounding the urethra (the tube that drains urine from the bladder during urination) weakens and does not close completely. Any activity that increases pressure on the bladder can cause urine to leak. The leaking stops when the activity stops.

In women, pregnancy and childbirth, a hysterectomy and a lack of estrogen after menopause can contribute to the problem. In men, stress urinary incontinence can be caused by prostate surgery or radiation treatment for prostate cancer, either of which can damage the bladder sphincter.

That figure includes men and women, and people of all ages, although most of those with urinary incontinence are over age 60.

Sometimes stress urinary incontinence is transient.

Many women wear sanitary pads or adult diapers and carry a change of clothing at all times. Embarrassed by the odor and fearful of possible accidents, millions of women with the condition stop doing activities they enjoy, such as socializing, having sex or exercising. This isolation deepens their sense of shame and loss of dignity.

Urge incontinence, also called hyperactive bladder or irritable bladder, is the inability to get to a toilet in time once you feel the urge to go. It occurs when nerve passages along the pathway from the bladder to the brain give the wrong the signal to the brain or the brain is unable to inhibit the bladder muscle from contracting, causing the bladder muscle to be unstable. Urge incontinence in women can be caused by complications from a hysterectomy. In men, the bladder muscle can become unstable by an enlarged prostate or by prostate surgery. In both sexes, it can be caused by aging, urinary infections, anxiety or depression.

Overflow incontinence refers to leakage that occurs when the quantity of urine produced exceeds the bladder's holding capacity. This happens when the bladder is not able to empty completely. This can be caused by a blockage that prevents the bladder from emptying completely, or by a weak bladder muscle that cannot contract enough to empty the bladder. Tumors in men or women or enlarged prostates in men can block the flow of urine out of the bladder. Some blood pressure medications can weaken the bladder muscle. Nerve damage to the spinal cord or pelvic nerves can also cause the bladder muscle to weaken.

Reflex incontinence is the loss of urine when the person is unaware of the need to urinate. It may result from an abnormal opening between the bladder and another structure, or from a leak in the bladder, urethra or ureter. It can also be caused by mental or physical disabilities that interfere with the normal signals from the nervous system to the bladder, such as Parkinson's disease, Alzheimer's disease and depression.

The good news is that the number is 80 percent. Many conditions can cause temporary urinary incontinence, including a urinary infection, drinking too many fluids (including caffeine), constipation, severe depression and restricted movement. The most common cause, however, is a side effect of medication. Medications that can cause temporary incontinence include terazosin, given for benign prostatic hypertrophy in men; oral decongestants that contain pseudoephedrine; drugs called beta-adrenergic blockers prescribed for hypertension or angina; diuretics; calcium-channel blockers; cochicine, used to treat gout; sedatives; antidepressants; antipsychotics; and antihistamines.

The treatment for urinary incontinence depends upon the type and cause of the incontinence. Diagnostic tests, which may include X-rays, blood work, urine analysis, bladder capacity checks, sphincter condition, urethral pressure and the amount of urine in the bladder after urination, help determine the type of incontinence. If you have stress incontinence and are a woman, you can help control your condition by doing Kegel exercises. These exercises strengthen the muscles around the neck of the bladder (the muscles you can use to stop the flow of urine when using the toilet). Tighten the muscles for four counts, then relax, repeating 10 to 20 times. For urge incontinence, the best way to handle your condition is to set a timer and use the bathroom on a regular schedule (a half-hour after a meal, two to three times between meals and before going to bed). Overflow incontinence, common in older men, can be prevented by treating an enlarged prostate when symptoms first appear.