Risk Factors:

About 20 million American women and 6 million men have urinary incontinence or have experienced it at some time in their lives. The number, however, may actually be higher because most patients are reluctant to discuss incontinence with their doctors. In fact, research indicates that many patients will not admit to having the problem even when questioned directly. Although a third of American men and women age 30 - 70 have had at least some loss of bladder control, most have not been diagnosed by a doctor.

In general, the main risk factors for urinary incontinence are:

• Female sex
• Older age
• Neurological disorder (such as stroke)

Higher body mass index, inactivity, depression, and diabetes can also increase risk.

Incontinence in Children and Young People

Incontinence is relatively uncommon in children 5 years and older. When incontinence does occur before puberty, it is twice as common in boys as in girls. Most young people who experience nighttime wetting do not have any serious physical or emotional disorders. It is often difficult to diagnose incontinence in children. Many cases result from a combination of factors, including:

• Birth defects or inborn conditions that cause problems in the urinary tract
• Slower physical development
• An overproduction of urine at night
• A lack of ability to recognize bladder filling when asleep
• Anxiety
• Inherited factors (indicated by a strong family history of bedwetting)

Bedwetting in children is not considered incontinence. However, bedwetting and other urinary problems in childhood may predict the later development of adult urinary incontinence.

Incontinence in the Elderly

All older adults are susceptible to incontinence. One in 10 people over age 65, and 3 in 10 over age 80, have some type of bladder control loss. About half of the elderly who are housebound or in nursing homes experience incontinence.

Incontinence in Women

Urinary incontinence is far more common among women than men. Between 15 - 50% of women experience urinary incontinence during their lifetimes, with the highest rates occurring in women who have had children. Severe urinary continence affects 7 - 10% of women. About 10% of women undergo surgery for urinary incontinence or pelvic organ prolapse.

Pregnancy and Childbirth. Pregnancy and childbirth can increase the later risk for urinary incontinence. The risk is highest with the first child, and there is an increased risk in women who have their first child over age 30. Vaginal birth can cause pelvic prolapse, a condition in which pelvic muscles weaken and the pelvic organs (bladder, uterus) slip into the vaginal canal. Pelvic prolapse, and the surgery used to correct it, can cause incontinence. However, it is not clear if cesarean delivery helps prevent urinary incontinence. Similarly, evidence is inconclusive as to whether episiotomy prevents urinary incontinence. (Episiotomy is a surgical incision that is made during childbirth to the perineum, the muscle between the vagina and the rectum. Doctors may perform this procedure to help widen the vaginal opening and prevent tearing.)

High-Impact Exercise. Women who engage in high-impact exercise are susceptible to urinary leakage, particularly women with a low foot arch. Shock to the pelvic area is increased as the foot makes impact with hard surfaces.

Smoking. Studies have reported a higher risk for incontinence, notably mixed incontinence, in women who are current or former heavy smokers (more than a pack a day).

Obesity. Being overweight is a major risk factor for all types of incontinence. The more a woman weighs, the greater her risk.

Medical Factors in Older Women. Urge incontinence is more common among postmenopausal women who have a history of:

• Diabetes
• Hysterectomy
• Two or more urinary tract infections within the past year

Incontinence in Men

The rate of incontinence in men (about 1.5 - 5%) is much lower than in women. The risk for urinary incontinence increases with age. In the United States, about 17% of men over age 60 have urinary incontinence. In older men, prostate problems and their treatments are the most common factors that affect the urinary tract. Up to 30% of men who have had surgery to remove their prostate gland experience some degree of urinary incontinence.

Factors in Temporary Incontinence

A number of conditions can cause temporary incontinence in anyone:

• Urinary tract infections
• Excess fluid intake
• Constipation
• Severe depression
• Restricted mobility

Drugs. Drugs are most often the cause of temporary incontinence.

• Drugs that affect the adrenergic system (a nerve-cell and hormonal pathway that regulates the sphincter muscle) are common causes of incontinence. For example, alpha-adrenergic blockers, such as terazosin (Hytrin), used for benign prostatic hypertrophy, can cause incontinence by over-relaxing the muscles. On the other hand, men with enlarged prostates who suffer from urinary problems may be helped by the increase of urine flow after using terazosin.
• Alpha-adrenergic agonists, such as pseudoephedrine (found in some oral decongestants) tighten the muscles and may cause overflow incontinence in susceptible people.
• Diuretics, used for high blood pressure, often rapidly introduce high urine volumes into the bladder.
• Colchicine, a drug used for gout, can cause urge incontinence.
• Other medications and substances that increase the risk for incontinence are caffeine, sedatives, antidepressants, antipsychotics, and antihistamines.