Stress Urinary Incontinence

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Involuntary loss of urine is reportedly experienced by upwards of 95% of women in their reproductive and post-menopausal years. This, however, does not mean that this overwhelming majority has urinary incontinence. To qualify as urinary incontinence (UI), the involuntary loss of urine must have a negative impact on the quality of the individual's life, particularly for hygienic and/or social standpoints. As such, the only person who can ultimately determine the presence of UI is the woman herself.

An estimated 15 to 20 million people in the United States have bladder control problems. This condition affects men and women, although it is nearly twice as common in women. The prevalence of this condition does increase with age. Fifteen to 30 percent of adults older than 60 years of age have UI.

The good news is that 80 to 90% of cases can be treated successfully. Although complete cure may not be attainable in all cases, substantial improvement can be expected in the vast majority.

Below you will find a significant amount of information on the more common causes of female urinary incontinence and associated pelvic organ prolapse (POP) conditions, including causes/predisposing factors, diagnostic evaluation, treatment options and suggestions for obtaining further information.

Types of urinary incontinence

Female urinary incontinence can be grouped in several distinct categories, although women often have symptoms found in more than one category:

  • Stress incontinence: Urine leakage occurs with increases in abdominal pressure (hence, mechanical “stress”).
  • Urge incontinence: Often referred to as "overactive bladder." Inability to hold urine long enough to reach a restroom.
  • Mixed incontinence: When two or more causes contribute to urinary incontinence. Often refers to the presence of both stress and urge incontinence.
  • Overflow incontinence: Leakage or “spillover” of urine when the quantity of urine exceeds the bladder's capacity to hold it.
  • Functional incontinence: Leakage (usually resulting from one or more causes) due to factors impairing reaching the restroom in time because of physical conditions (e.g., arthritis).

Definition of stress incontinence

Stress urinary incontinence (SUI) is loss of urine that occurs simultaneously with (at the same time as) physical activities that increase abdominal pressure (for instance: sneezing, coughing, laughing, and straining when performing). Many of the above-described activities lead to increased pressure within the abdominal cavity. This, in turn, increases the pressure within the bladder, which behaves like a balloon filled with liquid. The rise in bladder pressure has a tendency to force the urethra open and urine loss ensues. The amount of urine loss associated with SUI is usually small, ranging from mild seepage to drops to a large squirt.

Normal function of the urinary tract

The urethra has two functions: it serves as a pipeline from the bladder to the outside when you empty your bladder; it also is a valve that needs to stay closed in order for your bladder to retain urine.

Abnormalities to the urethra's closure mechanism are the primary cause of SUI. In most cases, support to the urethra is lacking. The front or anterior wall of the vagina acts as a backboard to the urethra. When you cough, laugh or strain, the pressure rise in the abdomen is transmitted simultaneously to the bladder and to the outside of the urethra. This mechanism compresses the urethra against the underlying front vaginal wall, effectively pinching the urethra closed (valve mechanism) and preventing loss of urine. If the front vaginal wall, especially beneath the urethra, is lax and moves too much (urethral hypermobility), the backboard valve mechanism is compromised. In fewer cases, the resistance provided by the urethra itself is low. The tiny muscles (smooth muscle cells) that make up the wall of the urethra lose their ability to maintain adequate resting tone and pressure and/or to squeeze (pressure rise) during stress-related events (e.g., coughing, straining, etc.). In menopausal patients, the once-abundant mucus in the urethral lining diminishes, which compromises the urethra's ability to seal closed. Any or all of these factors can play a role in the presence of SUI.

Predisposing factors to SUI

  • Gender
  • Genetic: inherited component of connective tissue (supportive tissue and muscle)
  • Vaginal birth trauma
  • Previous pelvic/vaginal surgery
  • Radiation therapy
  • Menopausal status
  • Chronic conditions: respiratory ailments, obesity, constipation, occupation/lifestyle (strenuous lifting)

In general, the causes of SUI are many. Listed above are factors that lead to SUI. You need to keep in mind that like pelvic organ prolapse, SUI does not result from any one of these factors, or from a single event.

There is little we can do (currently) regarding inheritance of genes for "weak" supportive tissues and muscles. However, if any of your immediate relatives experienced pelvic prolapse conditions or SUI, chances are good for you to develop these problems as well. Obstetricians are becoming more and more aware of the risks of injury to the pelvic floor caused by vaginal delivery. Excessive stretching of the supportive tissues, muscles and nerves can cause permanent defects even after post-pregnancy healing. This may lead to various pelvic floor support problems for the surrounding organs: bladder (cystocele), rectum (rectocele), and top of vagina and uterus (uterovaginal descensus/prolapse). Frequently, SUI is present in the period immediately following vaginal delivery. Although the SUI may resolve with time, its initial presentation may signal the development of more troublesome SUI in the future. Plus, the greater the number of vaginal deliveries (two or more), the greater the chance of POP and SUI in the future.

Previous pelvic/vaginal surgery for prolapse or radiation therapy to the area can lead to worsening urethral function in the future by interfering with the blood and nerve supplies to this delicate structure. Also, nearby surgeries like hysterectomy (removal of uterus), whether through an abdominal incision or vaginally, can cause injuries to the bladder and/or urethra. Fistulae (an abnormal tract/connection) between the two structures and the vagina can appear like SUI. Chronic conditions that lead to persistently elevated pressures in the abdomen can result or worsen SUI. Lung conditions (bronchial asthma, bronchitis), obesity, constipation, and occupation/lifestyle situations that involve heavy lifting or straining can lead to SUI. Loss of elasticity is an inevitable part of the normal aging process. This is known to be quickened by loss of estrogen stimulation once estrogen diminishes or ceases after natural or surgical menopause (i.e. removal of ovaries). In addition, decreased estrogen stimulation causes less mucus production by urethral glands, thereby compromising the urethral sealing ability.


An appropriate evaluation helps your physician or other healthcare provider pinpoint the type(s) of urinary incontinence you might have. An exhaustive evaluation is not always necessary. Your doctor/provider will determine what components will be important in your case.

The physical examination will involve the following:

  • Pelvic examination: a typical GYN examination to identify pelvic floor defects, including those of the front (cystocele), back (rectocele) and top walls (uterine and/or vaginal prolapse).
  • Urine specimen: obtained following voiding to determine how efficiently the bladder empties itself; a specimen is sent for bacterial culture (a urinary infection can cause or worsen urinary incontinence).
  • Cystoscopy (not always needed): the physician looks into the urethra and bladder with a small, illuminated telescope-like instrument to rule out stones, growths and foreign bodies (sutures from previous anti-incontinence surgery).
  • Urodynamics (not always needed): tests that measure pressures in the bladder and urethra simultaneously to tell how both components are working. They are done in an outpatient clinic, take 30 to 60 minutes, and are not painful.

Please note that you may not need all of the above tests for your healthcare professional to determine the type or cause of your incontinence.

Treatment options for SUI: Non-surgical

  • Absorbent pads/diapers.
  • Kegel exercises. Pelvic floor muscles act as a hammock or sling to buttress support to the urethra and bladder during stress related activities. Exercising these muscles improves the resting tone and strength of active contractions to help close the urethra when coughing or laughing. Innumerable Kegel exercise regimens are used but all have one thing in common: they must be done on a regular basis and indefinitely for the recipient to derive noticeable benefit.
  • Pessaries. These simple plastic shapes, worn in the vagina, were originally used only for pelvic organ prolapse. However, properly sized and incontinence modified pessaries can provide support beneath the urethra, compensating for the laxity of urethral support found in most SUI situations.
  • Urethral implant. Injection into the urethra of micro-beads is directed by a telescope-like device (urethroscope) to decrease the size of the gaping urethra. This creates a washer-like effect that assists in closing the urethra during coughing or straining. Unfortunately, more than one injection is usual.

Treatment options for SUI: Surgical

Many operations are available to cure SUI. These are intended to restore the support of the front vaginal wall immediately beneath the urethra thereby enhancing compression of the urethra against the backboard of the front vaginal wall. The sling, including TVT (tension-free vaginal tape), uses sutures and graft material (natural or synthetic) to provide cure rates as high as 95%, but these must be carefully selected for the specific type of SUI.

Additional information