Urinary Incontinence
Urinary incontinence is the uncontrollable loss of urine.
Urinary incontinence mostly affects older people but can occur at any age. It may affect as many as 1 of 5 younger adults to some extent; the rate rises to about 1 of 3 older people. In most age groups, urinary incontinence is more common in women than in men.
Urinary incontinence differs somewhat among age groups. Incontinence experienced by younger adults tends to begin suddenly, and it often resolves quickly with little or no treatment. Also, when younger adults experience incontinence, they usually maintain control without leakage for most of their episodes of urination. Older adults are often more frequently and severely affected. In addition, incontinence is less likely to resolve quickly or without treatment in older adults.
Although urinary incontinence is common, highly treatable, and very often curable, it is often not diagnosed or treated. People often live with incontinence without seeking professional help because they are afraid, embarrassed, or mistakenly believe it is a normal part of aging. A person with incontinence often feels isolated or depressed. In addition, urinary incontinence is often a reason for institutionalization because of the substantial burden it places on caregivers. More than 50% of nursing home residents are incontinent.
Urinary incontinence can lead to many complications. For example, incontinence that is not properly managed can contribute to the development of bladder and kidney infections. Particularly among older adults, incontinence can also increase the risk for skin rashes and pressure sores (because urine can irritate the skin), and falls (because an incontinent person may fall when rushing to use the toilet).
Control of Urination
The kidneys constantly produce urine, which flows through two tubes (the ureters) to the bladder, where urine is stored. The lowest part of the bladder (the neck) is encircled by a muscle (the urinary sphincter) that remains contracted to close off the channel that carries urine out of the body (the urethra), so that urine is retained in the bladder until it is full.
When the bladder is full, messages travel along nerves from the bladder to the spinal cord; they are then relayed to the brain and the person becomes aware of the urge to urinate. A person who has control of urination can then consciously and voluntarily decide whether to release the urine from the bladder or to hold it for a while. When the decision is made to urinate, the sphincter muscle relaxes, allowing urine to flow out through the urethra, and the bladder wall muscles contract to push the urine out. Muscles in the abdominal wall and floor of the pelvis can be contracted to increase the pressure on the bladder.
Several changes occur with age that affect the person's ability to control urination. The maximum amount of urine that the bladder can hold (bladder capacity) declines. A person's ability to postpone urination after feeling a need to urinate also decreases with age. The rate of urine flow out of the bladder and through the urethra slows. At any age, sporadic contractions of bladder wall muscles occur regardless of need or appropriate opportunity to urinate; most contractions are blocked by normal spinal cord and brain controls at younger ages, but the number that are not blocked increases with age. The amount of urine remaining in the bladder after urination is finished (residual urine) also increases with age. In women, the urethra shortens and its lining becomes thinner as the level of estrogen declines during menopause; these changes decrease the ability of the urinary sphincter to close tightly. In men, the prostate gland enlarges, sometimes impeding the flow of urine through the urethra. Although all of these age-related changes increase the odds that incontinence will occur, it usually only occurs when another factor is in place, for example, when the person has a medical disorder. Many disorders can impair or disrupt the ability to control urination.
Types and Causes
Incontinence can be categorized according to whether it started recently and suddenly (acute urinary incontinence) or slowly and gradually (chronic or acute urinary incontinence). A bladder infection is the most common cause of acute urinary incontinence. Several reversible factors can contribute to incontinence. Examples include conditions that result in confusion (a severe infection such as pneumonia) or impaired mobility (a leg or hip fracture). Other causes include excess intake of alcohol or beverages that contain caffeine and conditions that can result in irritation of the bladder or urethra, such as atrophic vaginitis or severe constipation. Persistent urinary incontinence may be caused by brain disorders such as stroke, diseases that affect the nerves leading to and from the bladder, conditions in the lower urinary tract, and conditions that impair mental function or mobility.
Urinary incontinence can also be categorized into five basic types based on the pattern of symptoms: urge, stress, overflow, functional, and mixed.
 See the table Drugs That May Cause or Worsen Urinary Incontinence.
Urge Incontinence: Urge incontinence is an abrupt and intense urge to urinate that cannot be suppressed, followed by an uncontrollable loss of urine. Some people experience the abrupt and intense urge to urinate but are still able to remain continent. People with urge incontinence usually have little time to get to the bathroom before they have an "accident." An illness or injury that interferes with mobility makes it even harder for a person to get to the bathroom quickly.
Urge incontinence is the most common type of persistent incontinence in older people and often has no clear cause. Urge incontinence in older people may be caused by a combination of overactivity of the muscles in the bladder along with poor squeezing ability of those muscles. Part of the cause of persistent urge incontinence relates to changes in the part of the brain in the frontal lobe that inhibits urination. These changes may accompany brain disorders, especially stroke and dementia, which disrupt the nervous system's ability to inhibit the bladder. Chronic overactivity of the bladder--overactive bladder--is common in older people and causes the abrupt and intense urge to urinate as well as frequent urination during the day and night.
Stress Incontinence: Stress incontinence is the uncontrollable loss of small amounts of urine when coughing, straining, sneezing, lifting heavy objects, or performing any maneuver that suddenly increases pressure within the abdomen. Stress incontinence is the most common type of incontinence among young and middle-aged women. It can be caused by weakness of the urinary sphincter, which sometimes results from childbirth, pelvic surgery, or an abnormal position of the urethra or uterus. In postmenopausal women, a lack of estrogen reduces the urethra's resistance to urine flow. In men, stress incontinence may follow prostate surgery if the upper part of the urethra or the bladder neck is injured. In both men and women, obesity can cause or worsen stress incontinence because extra weight stresses the bladder.
Some people with severe stress incontinence have nearly constant urine loss (sometimes referred to as total incontinence). In adults, this usually occurs because the urinary sphincter does not close adequately. Some children have total incontinence because a birth defect prevents the urethra from developing completely.
Overflow Incontinence: Overflow incontinence is the uncontrollable leakage of small amounts of urine, usually caused by some type of blockage or by weak contractions of the bladder muscles. When urine flow is blocked or the bladder muscles can no longer contract, the bladder becomes overfilled and enlarged. Pressure in the bladder increases until small amounts of urine dribble out.
In children, blockage of urine flow may be caused by narrowing of the end of the urethra or the bladder neck because of a birth defect. In men, an enlarged prostate can block the opening into the urethra from the bladder. Less commonly, blockage is caused by narrowing of the bladder neck or the urethra (urethral stricture), which may occur after prostate surgery. In men and women, constipation can cause overflow incontinence if stool fills the rectum to the point of putting pressure on the bladder neck and urethra. A number of drugs that affect the brain or spinal cord or that interfere with nerve messages, such as anticholinergic drugs and opioids, may impair bladder contractions and cause overflow incontinence. Nerve damage that paralyzes the bladder (neurogenic bladder) can also cause overflow incontinence. Diabetes mellitus can also cause a form of neurogenic bladder and overflow incontinence.
 See the sidebar Neurogenic Bladder: One Cause of Overflow Incontinence.
Functional Incontinence: Functional incontinence refers to urine loss resulting from the inability (or sometimes unwillingness) to get to a toilet. The most common causes are conditions that cause immobility, such as stroke or severe arthritis, and conditions that interfere with mental function, such as dementia due to Alzheimer's disease. In rare situations, people may become so depressed or otherwise emotionally disturbed that they do not go to the toilet. This is sometimes referred to as psychogenic incontinence.
Mixed Incontinence: Mixed incontinence involves more than one type of incontinence. For example, a child may have incontinence resulting from both nerve damage and psychologic factors. A man may have overflow incontinence from prostate enlargement and urge incontinence from a stroke. The most common type of mixed incontinence occurs in older women, who often have a mixture of urge and stress incontinence.
Diagnosis
As a first step, a doctor asks specific questions about the history of the problem. The doctor also asks how much the incontinence is affecting the person's quality of life and ability to function. These questions can help the doctor determine the cause of the problem and guide an appropriate treatment plan.
A person with urinary incontinence may be asked to record the pattern of urination for at least 3 days (a "bladder diary"). This diary can help the doctor evaluate the cause of the incontinence. Useful information for the doctor might include how often and when the person urinates, whether or not control was lost, and estimates of how much urine leaked when incontinence did occur.
A physical examination can provide valuable information. A rectal examination can confirm whether the person is severely constipated. A pelvic examination in women can help identify problems that may contribute to or cause incontinence, such as atrophy of the lining of urethra and prolapse of the bladder (cystocele). Stress incontinence is sometimes diagnosed simply by observing the loss of urine while the person is coughing or straining. The amount of urine left in the bladder after urination (residual urine) can be measured using ultrasound or urinary catheterization (placing a small tube called a catheter into the bladder). A large amount of residual urine indicates an obstruction or a problem with nerves or the bladder muscle, which may indicate overflow incontinence. Urinalysis is performed to determine whether an infection is present.
For some people, special tests during urination (urodynamic evaluation) may be helpful. These tests measure the pressure in the bladder at rest and when filling. A catheter is inserted through the urethra into the bladder and water is passed through the catheter while the pressure within the bladder is recorded. Normally, the pressure increases slowly. In some people, pressure builds in sudden spasms or rises too sharply before the bladder is completely filled. The pattern of pressure change helps the doctor determine the type of incontinence and the best treatment. The rate of urine flow can also be measured; this measurement can help determine whether urine flow is obstructed and whether the bladder muscles can contract strongly enough to expel the urine.
Treatment
Treatment varies according to the type and cause of incontinence. Most people can be either cured or helped considerably.
The person should receive education about bladder functioning, the effects of medications and fluid intake, and bladder and bowel habits. Treatment often requires taking only some simple steps to change behavior, such as deliberately urinating at regular intervals--every 2 to 3 hours--to keep the bladder relatively empty. Avoiding fluids that may irritate the bladder, such as beverages that contain caffeine, may help. The person should drink adequate amounts of fluids (six to eight 8-ounce glasses a day) to prevent the urine from becoming too concentrated--which can irritate the bladder. Drugs that adversely affect bladder function can often be discontinued. For people taking diuretics, the timing of the dose can be adjusted so that the person can be close to a bathroom when the drug takes effect.
Specially designed incontinence pads and undergarments can protect the skin and enable people to remain dry, comfortable, and socially active. These items are unobtrusive and readily available.
Episodes of urge incontinence often can be prevented by urinating at regular intervals before the urge occurs (scheduled voiding). Bladder training techniques, which include pelvic muscle (Kegel) exercises, can be very helpful. Learning how to contract these muscles is not easily self-taught, so biofeedback is often used to help with training. Nurses or physical therapists can help teach these exercises. The exercises involve repeatedly contracting the muscles many times a day to build up strength and learning to use the muscles properly in situations that cause incontinence, such as coughing.
Drugs that relax the bladder may help. The two most commonly used drugs of this class are oxybutynin and tolterodine. Both can be taken once a day. Although these drugs can help by reducing bladder irritability and the strong urge to urinate, they have potential side effects, such as dryness of the mouth, constipation, gastroesophageal reflux, or even retention of urine.
For people with stress incontinence, urinating frequently to avoid a full bladder and pelvic muscle (Kegel) exercises are usually helpful. In women with stress incontinence, applying estrogen cream to the vagina or taking estrogen tablets may be helpful. Other drugs that help tighten the sphincter, such as pseudoephedrine, should be used with estrogen. Incontinence pads may be used to absorb the small amount of urine that usually leaks during stress.
More severe cases of stress incontinence that do not respond to treatment can be corrected surgically using any of several procedures that lift up the bladder and strengthen the bladder outlet (the portion of the bladder that empties into the outflow passage or urethra). Injections of collagen around the urethra are effective in some cases. A urinary sphincter that does not close adequately may be replaced with an artificial one.
For overflow incontinence caused by an enlarged prostate or other blockage, surgery is usually necessary. A variety of procedures are available to remove part or all of the prostate. The drug finasteride, when taken over a period of months, can reduce the size of the prostate or stop its growth, so that surgery can be avoided or deferred. Drugs that relax the sphincter, such as terazosin and tamsulosin, can be quite effective.
When the cause of overflow incontinence is weak contraction of the bladder muscles, drugs are usually not helpful. Gentle pressure applied by squeezing the lower abdomen with the hands just over the bladder may help, especially for people who can empty the bladder but have difficulty emptying it completely. In some cases, a catheter may need to be inserted into the bladder to drain the bladder and prevent complications, such as recurring infections and kidney damage. The catheter may be placed permanently, or it may be inserted and removed several times a day.
Treatment for functional incontinence involves regular toileting assistance. For example, another person can remind the incontinent person to urinate on a schedule, usually every 3 to 4 hours, so that the bladder is emptied before episodes of incontinence can occur (prompted scheduled voiding). If depression is a contributing factor, it should be treated. The use of garments and pads is also helpful; however, a person should not become unnecessarily dependent on them.
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