Bladder problems, long a nuisance and source of embarrassment to millions of Americans, are now being recognized as a problem with serious medical consequences as well.

An estimated 33 million Americans – 11% of the population – have “overactive bladder,” which includes both a strong urge to urinate without actual leakage, and “urge incontinence,” in which that strong urge is accompanied by leakage.

It’s now clear that people with overactive bladders have 2.5 times the risk of falling as people the same age without the problem, and 1.5 times the risk of breaking a bone, said Dr. Donald Ostergard, a professor of obstetrics and gynecology at the University of California, Irvine. Often, falls occur at night as people rush to the bathroom.

Urinary incontinence is also among the top three reasons for admission to a nursing home, according to the National Association for Continence (www.nafc.org). Among patients already in nursing homes, roughly half are incontinent. Meanwhile, caring for incontinent patients in nursing homes has become so expensive – someone has to change the bed and diapers several times a night – that some homes deny admission to incontinent patients, said Dr. Neeraj Kohli , director of urogynecology at Brigham and Women’s Hospital.

Urinary incontinence also increases the risk of bladder and skin infections, as well as depression and social isolation. Some people “don’t go out. They don’t remarry. I had a patient yesterday who said she’d rather be dead than wetting herself all the time,” said Dr. William Steers, chairman of urology at the University of Virginia School of Medicine.

In addition to “urge” problems caused by muscle spasms in the bladder, millions of Americans also suffer from “stress” incontinence, which means they leak urine with exertion, like coughing or jumping.

The enormity of this problem has not been lost on industry. Eager drug makers, surgical device creators, and adult diaper manufacturers have turned these embarrassing bladder problems into a $24 billion a year industry.

With a growing array of treatments – including new drugs – becoming available, the trick now is to figure out which kind of bladder problem you have and sort out the risks and benefits of the treatments offered.

For stress incontinence, in which the muscular support of the bladder neck is weak, a study of 20 women by Austrian researchers recently showed that taking stem cells from a muscle in the arm, cultivating them in the lab, then re-injecting them into the urethral sphincter can markedly reduce the problem. The cells, much like collagen injections, bulk up the sphincter, allowing it to close more tightly. A new trial is now starting in Canada and – if the U.S. Food and Drug Administration approves – in America as well, said one of the researchers, Dr. Michael Chancellor, a professor of urology at the University of Pittsburgh Medical Center.

So far there are no drugs on the American market for stress incontinence. But duloxetine (to be marketed as Yentreve), which boosts levels of serotonin and norepinephrine in the area of the spinal cord that controls the urinary sphincter, is awaiting FDA approval, said Dr. Anurag Da, director of the center for neurourology and continence at Beth Israel Deaconess Medical Center in Boston. The drug – which can be prescribed now because it is already on the market as Cymbalta for depression – can cause dry mouth and, in some patients, nausea.

There are also roughly 200 surgical procedures that use sutures, slings, and “bulking agents” to support the sagging bladders prone to stress incontinence. Some new techniques are minimally invasive, outpatient procedures that appear highly effective, though these fixes for the anatomical problems underlying tress incontinence can lead to the muscle spasm problems of urge incontinence, noted Dr. Steers.

For overactive bladder, the problem is not a weak sphincter, but uncontrollable spasms in bladder muscles. Caffeine and increased fluid intake can also trigger overactive bladder.

There are a number of drug options. The old standbys are Detrol (tolterodine) and Ditropan (oxybutynin), which stop spasms by blocking acetylcholine, a chemical that makes muscles contract. But these drugs can cause dry mouth, constipation, dry eyes, and headaches.

Two recently approved, more selective drugs that work basically the same way, but with fewer side effects, are Vesicare (solifenacin) and Sanctura (trospium). Another, Enablex (darifenacin), is expected to be approved soon.

Another treatment for urge incontinence involves stimulating the nerves in the spinal cord that control urination, kind of like “fancy acupuncture,” said Dr. Das. One such procedure involves inserting a device called InterStim in the lower back near the sacral nerve to inhibit the firing of bladder nerves. Another option is to inject Botox into the bladder.

Lower tech approaches can also help with stress incontinence, including exercises to strengthen muscles that support pelvic organs. Behavioral techniques, such as biofeedback, may help with both stress incontinence and overactive bladder.

Ms. Foreman is a lecturer on medicine at Harvard Medical School. Her columns are available at www.myhealthsense.com.