Many things can go wrong with the complex system that allows us to control urination. Incontinence is categorized by the type of problem and, to a lesser extent, by differences in symptoms.
Types of Incontinence
If urine leaks out when you jump, cough, or laugh, you may have stress incontinence. Any physical exertion that increases abdominal pressure also puts pressure on the bladder. The word “stress” refers to the physical strain associated with leakage. It has nothing to do with emotion.
Often only a small amount of urine leaks out. In more severe cases, the pressure of a full bladder overcomes the body’s ability to hold in urine. The leakage occurs even though the bladder muscles are not contracting and you don’t feel the urge to urinate.
Stress incontinence develops when the urethral sphincter, the pelvic floor muscles, or both these structures have been weakened or damaged and cannot dependably hold in urine. Stress incontinence is divided into two subtypes.
- In urethral hypermobility, the bladder and urethra shift downward when abdominal pressure rises, and there is no hammock-like support for the urethra to be compressed against to keep it closed.
- In intrinsic sphincter deficiency (urethral incompetence), problems in the urinary sphincter keep it from closing fully or allow it to pop open under pressure.
Many experts believe that women who have delivered a baby vaginally are more likely to develop stress incontinence because giving birth has stretched and possibly damaged the urethral sphincter muscles and nerves. Generally, the larger the baby, the longer the labor, the older the mother, and the greater the number of births, the more likely that incontinence will result
Age is likewise a factor in stress incontinence. As a woman gets older, the muscles in her pelvic floor and urethra weaken, and it takes less pressure for the urethra to open and allow leakage. Declining estrogen can also play some role, although it is not clear how much. Many women do not experience symptoms until after menopause. In men, the most frequent cause of stress incontinence is urinary sphincter damage sustained through prostate surgery or a pelvic fracture. Lung conditions that cause frequent coughing, such as emphysema and cystic fibrosis, can also contribute to stress incontinence in both men and women.
Overactive bladder (urge incontinence)
If you feel a strong urge to urinate even when your bladder isn’t full, your incontinence might be related to overactive bladder, sometimes called urge incontinence or urgency incontinence. This condition occurs in both men and women and involves an overwhelming urge to urinate immediately, frequently followed by loss of urine before you can reach a bathroom. Even if you never have an accident, urgency and urinary frequency can interfere with your work and social life because of the need to keep running to the bathroom.
Urgency occurs when the bladder muscle, the detrusor, begins to contract and signals a need to urinate, which can happen even when the bladder is not full. Another name for this phenomenon is detrusor overactivity.
Overactive bladder can result from physical problems that keep your body from halting involuntary bladder muscle contractions. Such problems include damage to the brain, the spine, or the nerves extending from the spine to the bladder—for example, from an accident, diabetes, or neurological disease. Irritating substances within the bladder, such as those produced during an infection, might also cause the bladder muscle to contract.
Most often there is no identifiable cause for overactive bladder, but people are more likely to develop the problem as they age. Postmenopausal women, in particular, tend to develop this condition, perhaps because of age-related changes in the bladder lining and muscle. African American women with incontinence are more likely to report symptoms of overactive bladder than stress incontinence, while the reverse is true in white women.
A condition called myofascial pelvic pain syndrome has been identified with symptoms that include overactive bladder accompanied by pain in the pelvic area or a sense of aching, heaviness, or burning.
In addition, infections of the urinary tract, bladder, or prostate can cause temporary urgency. Partial blockage of the urinary tract by a bladder stone, a tumor (rarely), or, in men, an enlarged prostate (a condition known as benign prostatic hyperplasia, or BPH) can cause urgency, frequency, and sometimes urge incontinence. Surgery for prostate cancer or BPH can trigger symptoms of overactive bladder, as can freezing (cryotherapy) and radiation seed treatment (brachytherapy) for prostate cancer.
Neurological diseases (such as Parkinson’s disease and multiple sclerosis) can also result in urge incontinence, as can a stroke. Three months after being discharged from the hospital following a stroke, about 44% of patients have incontinence; by one year later, 38% do.
If you have symptoms of both overactive bladder and stress incontinence, you likely have mixed incontinence, a combination of both types. Most women with incontinence have both stress and urge symptoms—a challenging situation. Mixed incontinence also occurs in men who have had prostate removal or surgery for an enlarged prostate, and in frail older people of either sex.
If your bladder never empties adequately, you might experience urine leakage, with or without feeling a need to go. Overflow incontinence occurs when something blocks urine from flowing normally out of the bladder, as in the case of prostate enlargement that partially closes off the urethra. It can also occur in both men and women if the bladder muscle (detrusor) becomes underactive (the opposite of an overactive bladder).
When that happens, you don’t feel an urge to urinate, and the bladder is unable to push out most of the urine. Eventually the bladder becomes overfilled, or distended, and the urine leaks out. The bladder might also spasm at random times, causing leakage. This condition is sometimes related to diabetes or cardiovascular disease.
Men are much more frequently diagnosed with overflow incontinence than women because it is often caused by prostate-related conditions. In addition to enlarged prostate, other possible causes of urine blockage include tumors, bladder stones, or scar tissue. If a woman has severe prolapse of her uterus or bladder (meaning that the organ has dropped out of its proper position), her urethra can become kinked like a bent garden hose, interfering with the flow of urine. This can also happen if a woman has had surgery for stress incontinence.
Nerve damage (from injuries, childbirth, past surgeries, radiation treatment, or diseases such as diabetes, multiple sclerosis, or shingles) and aging often prevent the bladder muscle from contracting normally. Medications that prevent bladder muscle contraction or that make you unaware of the urge to urinate can also result in overflow incontinence.
If your urinary tract is functioning properly but other illnesses or disabilities are preventing you from staying dry, you might have what is known as functional incontinence. For example, if an illness rendered you unaware or unconcerned about the need to find a toilet, you would become incontinent. Medications, dementia, or mental illness can decrease awareness of the need to find a toilet.
Even if your urinary system is fine, it can be extremely hard for you to avoid accidents if you have trouble getting to a toilet. This problem can affect anyone with a condition that makes it excessively difficult to move to the bathroom and undress in time. This includes problems as diverse as having arthritis, being hospitalized or restrained, or being too far away from a toilet.
If a medication (such as a diuretic used to treat high blood pressure or heart failure) causes you to produce abnormally large amounts of urine, you could develop incontinence that requires a change in treatment, such as taking your diuretic earlier in the day to avoid getting up at night to urinate. If you make most of your urine at night, the result might be nocturnal (nighttime) enuresis, or bedwetting.
Reflex incontinence occurs when the bladder muscle contracts and urine leaks (often in large amounts) without any warning or urge. This can happen as a result of damage to the nerves that normally warn the brain that the bladder is filling. Reflex incontinence usually appears in people with serious neurological impairment from multiple sclerosis, spinal cord injury, other injuries, or damage from surgery or radiation treatment.
Do you get an overwhelming urge to urinate just when you arrive home and start to open the door? Also called “latchkey incontinence,” this phenomenon is a good demonstration of the bladder-brain connection. When you feel the urge to urinate as you’re going home, you suppress it until you arrive. Eventually, the bladder becomes conditioned to associate arriving home with urinating, and the urge comes on whether or not your bladder is full. This is not a “psychological” problem, but a reflex-conditioning problem, much as when you salivate upon smelling something good to eat.
The childbirth connection
It’s a little-known fact that many childbirth classes fail to adequately cover: some women who give birth vaginally go on to develop one or more of the problems collectively known as pelvic floor disorders. These include stress incontinence, overactive bladder, uterine prolapse (in which the uterus drops out of its normal position), anterior vaginal prolapse (also called cystocele, in which the bladder bulges through a weakened vaginal wall), posterior vaginal prolapse (also called rectocele, in which the rectum bulges through a weakened vaginal wall), and fecal incontinence. Both cystocele and rectocele can be thought of as types of hernias. These disorders often grow worse over time, and one out of 10 women eventually undergoes a surgical repair.
Vaginal delivery can lead to pelvic floor damage as the baby stretches the pelvic floor muscles and other tissues on its way through the birth canal, sometimes causing tearing or other damage. Research shows that a number of factors raise the risk of damage for women who deliver vaginally, including these:
- older age of the mother
- greater weight of the baby
- higher number of vaginal births
- longer second stage of labor (the pushing stage)
- vaginal delivery assisted by forceps or a vacuum device
- episiotomy (a surgical cut made to expand the vaginal opening during vaginal delivery)
What are the solutions?
Delivery by cesarean section sometimes protects against severe incontinence. However, the difference in urinary incontinence rates following cesarean versus vaginal delivery tends to diminish within a few years of giving birth. For example, a 2013 study found that the same percentage of women had incontinence two years after delivering their first baby, whether vaginally or by elective cesarean section.
A review from Norway evaluated the benefit of various strategies for avoiding incontinence after childbirth. Women were less likely to experience incontinence after childbirth if they were nonsmokers, were of normal weight before pregnancy and returned to that weight afterward, did not experience constipation during or after pregnancy, and performed pelvic muscle exercises during and after pregnancy.
The use of episiotomy during childbirth has declined steadily, but millions of women have had episiotomies in the past. It was previously believed that an episiotomy helped prevent tearing of the vagina and damage to the pelvic floor. However, evidence has failed to confirm any benefit. And an episiotomy may cause more damage than it prevents. For example, studies in the journal Obstetrics and Gynecology found that women who had an episiotomy during their first or subsequent deliveries were more likely to experience tears in the anal sphincter. After sphincter tear and repair, about half of women experience fecal or gas incontinence. For many women, the symptoms improve or disappear within a few months, but others sustain persistent or worsening problems, or find that symptoms reappear after subsequent deliveries.
Besides episiotomy, other major factors contributing to sphincter tears were larger babies, a prolonged second stage of labor, and forceps delivery. Vacuum delivery had a smaller risk of sphincter tear than forceps delivery. Gentle delivery techniques and slow, gradual induction (when induction is necessary) would go a long way toward sparing women incontinence resulting from childbirth. For example, the Norwegian review found good evidence that using warm packs on the perineum (the tissue between the anus and vulva) during delivery can reduce the risk of later incontinence.