Stress incontinence is an involuntary loss of urine that occurs during physical activity, such as coughing, sneezing, laughing, or exercise.

Incontinence - stress

The ability to hold urine and maintain continence depends on the normal function of the lower urinary tract, the kidneys, and the nervous system. Additionally, the person must have the ability to recognize and appropriately respond to the urge to urinate.

Stress incontinence is a bladder storage problem in which the strength of the muscles (urethral sphincter) that help control urination is reduced. The sphincter is not able to prevent urine flow when there is increased pressure from the abdomen.

Stress incontinence may occur as a result of weakened pelvic muscles that support the bladder and urethra or because of malfunction of the urethral sphincter. The weakness may be caused by prior injury to the urethral area, neurological injury, some medications, or after surgery of the prostate or pelvic area.

Stress urinary incontinence is the most common type of urinary incontinence in women. Studies have shown about 50% of all women have occasional urinary incontinence, and as many as 10% have frequent incontinence. Nearly 20% of women over age 75 experience daily urinary incontinence.

Stress incontinence is often seen in women who have had multiple pregnancies and vaginal childbirths, whose bladder, urethra, or rectal wall stick out into the vaginal space (pelvic prolapse).

Risk factors for stress incontinence include:

• Being female
• Getting older
• Childbirth
• Smoking
• Obesity
• Chronic coughing (such as chronic bronchitis and asthma)

Involuntary loss of urine is the main symptom. It may occur when:

• Coughing
• Sneezing
• Standing
• Exercising
• During other physical activity

The health care provider will perform a physical exam, including a rectal exam, a genital exam in men, and a pelvic exam in women. In some women, a pelvic examination may reveal that the bladder or urethra is bulging into the vaginal space.

Tests may include:

• Post-void residual (PVR) to measure amount of urine left after urination
• Urinalysis or urine culture to rule out urinary tract infection
• Urinary stress test (the patient is asked to stand with a full bladder, and then cough)
• Pad test (after placement of a pre-weighed sanitary pad, the patient is asked to exercise -- following exercise, the pad is re-weighed to determine the amount of urine loss)
• A pelvic or abdominal ultrasound
• X-rays with contrast dye of the kidneys and bladder
• Cystoscopy (inspection of the inside of the bladder)
• Urodynamic studies (tests to measure pressure and urine flow)
• Rarely, an EMG (electromyogram) is performed to study muscle activity in the urethra or pelvic floor

Other tests may include the measurement of the change in the angle of the urethra when at rest and when straining (Q-tip test). An angle change of greater than 30 degrees often means there is significant weakness of the muscles and tissues that support the bladder.