Urinary incontinence is an inability to hold your urine until you get to a toilet. It is often temporary, and it may be associated with an underlying medical condition.

Women experience incontinence twice as often as men. Pregnancy and childbirth, menopause, and the structure of the female urinary tract account for this difference. But both women and men can become incontinent from neurologic injury, birth defects, strokes, multiple sclerosis, and physical problems associated with aging.

Older women, more often than younger women, experience incontinence. But incontinence is not inevitable with age. Incontinence is treatable and often curable at all ages. If you experience incontinence, you may feel embarrassed. It may help you to remember that loss of bladder control can be treated. You will need to overcome your embarrassment and see a doctor to learn if you need treatment for an underlying medical condition.

During urination, muscles in the wall of the bladder contract, forcing urine out of the bladder and into the urethra. At the same time, sphincter muscles surrounding the urethra relax, letting urine pass out of the body (see figure 1). Incontinence will occur if your bladder muscles suddenly contract or muscles surrounding the urethra suddenly relax.

What are the types of incontinence?

Stress Incontinence

It is the most common form of incontinence in women and is treatable.

Pelvic floor muscles support your bladder (see figure 2). If these muscles weaken, your bladder can move downward, pushing slightly out of the bottom of the pelvis toward the vagina. This prevents muscles that ordinarily force the urethra shut from squeezing as tightly as they should. As a result, urine can leak into the urethra during moments of physical stress. Stress incontinence also occurs if the muscles that do the squeezing weaken.

Urge Incontinence
If you lose urine for no apparent reason while suddenly feeling the need or urge to urinate, you may have urge incontinence. The most common cause of urge incontinence is inappropriate bladder contractions.

Medical professionals describe such a bladder as "unstable," "spastic," or "overactive." Your doctor might call your condition "reflex incontinence" if it results from overactive nerves controlling the bladder.

Involuntary actions of bladder muscles can occur because of damage to the nerves of the bladder, to the nervous system (spinal cord and brain), or to the muscles themselves. Multiple sclerosis, Parkinson's disease, Alzheimer's disease, stroke, and injury--including injury that occurs during surgery--all can harm bladder nerves or muscles.

Functional Incontinence
People with functional incontinence may have problems thinking, moving, or communicating that prevent them from reaching a toilet. A person with Alzheimer's disease, for example, may not think well enough to plan a timely trip to a restroom. A person in a wheelchair may be blocked from getting to a toilet in time. Conditions such as these are often associated with age and account for some of the incontinence of elderly women in nursing homes.

Overflow Incontinence
If your bladder is always full so that it frequently leaks urine, you have overflow incontinence. Weak bladder muscles or a blocked urethra can cause this type of incontinence. Nerve damage from diabetes or other diseases can lead to weak bladder muscles; tumors and urinary stones can block the urethra. Overflow incontinence is rare in women.

Other Types of Incontinence
Stress and urge incontinence often occur together in women. Combinations of incontinence--and this combination in particular--are sometimes referred to as "mixed incontinence."

"Transient incontinence" is a temporary version of incontinence. It can be triggered by medications, urinary tract infections, mental impairment, restricted mobility, and stool impaction (severe constipation), which can push against the urinary tract and obstruct outflow.