Disorders of the urinary system -- including urinary incontinence -- may be caused by illness, injury, or age-related physical changes, such as decreased kidney function, loss of muscle strength in the urinary tract, and increased numbers of urinary infections. However, urinary incontinence is not a certain consequence of growing old and can occur at any age.

Many forms of urinary incontinence are short-term and can be managed with simple therapy. Some temporary causes of urinary incontinence include:

• Infection and/or inflammation of the urinary tract, vagina or prostate

• Constipation (impacted stool)

• Psychological factors

• Mental delirium (confusion)

• Polyuria (increased production of urine)

• Limited mobility

• Side effects of medications

Urinary incontinence that is longer lasting or chronic may be caused by conditions such as:

• Weakness of the muscles that support the bladder

• Weakness of the bladder itself

• Weakness of the sphincter muscles that surround the urethra

• Overactive bladder muscles

• Blocked urethra due to prostate enlargement

• Nerve disorders or injuries

• Birth defects

• Hormone imbalances in women

In addition, some unlikely diseases and medications have been linked with urinary incontinence. Each case will vary, depending upon factors such as the time course of the incontinence, as well as the age, gender and the medical history of the affected person.

Below is a list of the most common risk factors for urinary incontinence. To find out more about a risk factor, and how it might cause urinary incontinence, click on the title.

• Childbirth

• Menopause

• Pelvic Surgery

• Diabetes mellitus

• Decreased Mobility

• Diuretic Medications

Childbirth
In women, incontinence is often related to pregnancy and childbirth, which can flatten, stretch and weaken many of the pelvic floor muscles that provide the necessary support to the bladder neck and urethra, and are therefore important in urination. But, if a woman loses bladder control immediately after childbirth, she should not despair. The pelvic floor muscles may just need time to recover, and the incontinence may go away by itself.

If incontinence continues after 6 weeks, a physician should be contacted. Without proper treatment, urinary incontinence can become a chronic problem.

Incontinence also may be caused by other aspects of pregnancy and childbirth, such as a changed position of the bladder and urethra, episiotomy (a cut made in the pelvic floor/vagina, which makes it easier for the baby to come out), or damage to the bladder control nerves. Studies suggest that the more vaginal births (births through the reproductive canal; non-caesarean births) a woman has had, the more likely she is to leak urine during physical activity.

Women who exercise the pelvic floor muscles usually have fewer bladder problems than those who do not. Bladder control problems do not necessarily occur immediately after childbirth. Some women do not begin to experience incontinence problems until months or years after they have borne children.

Menopause
Between 45 and 55 years of age, most women's ovaries (egg-containing glands) stop making estrogen: the female sex hormone that regulates monthly menstrual periods and controls how the body matures and adapts during pregnancy and breast-feeding. This reduction in estrogen causes menopause (the end of monthly menstrual periods). Lack of estrogen can result in a urethra with a thin lining that does not close properly. Lack of estrogen also makes the bladder muscles weaken. The combination of a thin, injury-prone urinary tract and weak bladder muscles can cause the urethra to open unexpectedly during physical activity, leading to stress incontinence.

Some of the signs of menopause-related bladder changes include:

• strong, urgent need to pass urine

• frequent need to pass urine

• painful urination

Fortunately, estrogen products are available for the treatment of incontinence caused by menopause. Women who have such incontinence have the option of choosing from a number of different forms of estrogen. However, every woman who thinks about using estrogen therapy should discuss the pros and cons with her physician. Estrogen products are available only by prescription.

Pelvic Surgery
Like pregnancy and childbirth, pelvic surgery can weaken and damage the pelvic floor muscles. As a result, the pelvic floor muscles may no longer be able to provide the necessary support to the bladder neck and urethra, and these structures may drop freely when downward pressure is applied. This condition, which is known as hyper mobility, causes incontinence during physical activity, when the urethra cannot close tightly enough to resist increased abdominal pressure on the bladder.

Urinary incontinence can result from common forms of pelvic surgery, including abdominal resection for colorectal (intestinal) cancer, gynecologic (female genital tract) surgery such as radical hysterectomy (complete removal of the uterus) or hysterectomy for benign (noncancerous) disease, and failed prolapsed (restabilization) surgery for stress urinary incontinence.

Most patients with postoperative incontinence have either detrusor instability (DI or unstable bladder: an involuntary, downward-pushing contraction of the bladder) or urethral/bladder neck incontinence (abnormal function) due to nerve damage. Successful management of DI incontinence usually can be achieved by drug therapy and urinary catheterization (passage of a tube through the urethra into the bladder to drain urine into a bag outside the body); patients with bladder neck incontinence may require additional surgical measures.

Diabetes mellitus
Diabetes mellitus is a disease that is characterized by producing large amounts of urine. The bodily changes caused by diabetes can result in nerve damage that affects the bladder. The bladder malfunction specifically associated with diabetes mellitus is called diabetic cystopathy. Diabetic cystopathy progresses with few noticeable symptoms, although patients may lose bladder sensation. Over time, impaired bladder sensation may lead to increased bladder volume and overdistension (overstretching), urinary retention (bladder-emptying) problems, and overflow incontinence. The few existing treatments for diabetic cystopathy include catheterization, timed voids and control of hyperglycemia (too much blood sugar).

Decreased Mobility
Decreased mobility is a cause of functional incontinence in older people who have relatively normal bladder control but who have difficulty reaching the toilet in time because of physical disorders (for example, arthritis and other crippling conditions) or mental disabilities.

Diuretic Medications
Diuretics, or water pills, are prescribed by physicians to increase the amount of urine that is released from a patient's body. Diuretics are commonly used for the treatment of conditions such as hypertension (high blood pressure) and edema (abnormal build-up of fluid in the body). Unfortunately, rapid-acting diuretics can increase the urgency and frequency of urination in some people, particularly those who are elderly and/or bedridden. Urinary incontinence may result.

The unwanted side effects of diuretics can be remedied by lowering or modifying the dosage of the medication: for example, by flexible scheduling of rapid-acting diuretics.