Why Women Are Susceptible
Urinary tract infections occur 25 times more often in women than in men. Between the ages of 20 and 50, women have UTIs 50 times more often than men. Each year, UTIs are the reason for more than 5 million visits to the doctor in the United States. By the first few years after menopause, 1 out of 10 women can expect to have had a bladder infection or worse. Why is this so?
Anatomy
One reason women are so suseptible can be found in the physical makeup of the human body. Infections in the urinary tract generally start when bacteria enter from outside. The bacteria that cause about 9 out of 10 urinary tract infections, Escherichia coli (abbreviated E. coli), are normally found in the lower intestine, their natural home. The trouble starts when they move into the urethra and up into the bladder.
In both men and women, E. Coli leaving the body through the rectum can sometimes re-enter through the urethra. If they succeed in reaching the bladder, they then find a warm, moist environment in which to settle and multiply rapidly. However, because a woman's urethra, at 1 inch long, is far shorter than a man's (which runs the full length of the penis) bacteria invading a woman's urinary tract have a much shorter trip and a far better chance of getting established.
Toilet Habits
After urination or a bowel movement, bacteria can enter the urethra through the vagina in two ways. First, wiping from back to front with toilet tissue can bring bacteria directly into the entrance of the urinary tract. Second, even if you keep your rectal area very clean, E. coli can reside in your underwear and work their way around to the vaginal area during exercise.
Sex
The thrusting of sexual intercourse, especially with both anal and vaginal entry, can spread bacteria throughout your genital area while temporarily traumatizing the urethra. The more prolonged or vigorous the thrusting, the more it is likely to open the door to infection. In fact, many women who suffer from repeated bouts of urinary tract infection start to realize that the pain begins within 12 to 24 hours after sex.
Sexual activity doesn't have to be unusually forceful to induce an infection. Women who have recently embarked on an active sex life, either for the first time or more intensively than usual—as newlyweds, for example, or on vacation—frequently find themselves with UTIs, specifically, with bladder infections. That's where the term honeymoon cystitis comes from.
Barrier methods of contraception can irritate sensitive vaginal and urinary tissue as well, and irritated tissue helps create an environment where bacteria can thrive. In addition, the active ingredient in most spermicidal foams and jellies, nonoxynol 9, kills some of the vagina's beneficial bacteria, allowing the bacteria that cause cystitis to colonize. Furthermore, a diaphragm can also press against the urethra, and cause irritation. Some women are allergic to the latex in condoms or to the spermicides contained in some condoms. (Oral contraceptives have also been found to predispose women to UTIs. Fortunately, today's low-dose pill is less likely to do this than the higher-dose pills of the past.)
WHY UTIs HIT WOMEN HARDEST
It's simply a matter of distance: Bacteria travel no more than a few inches to reach the friendly environment of a woman's bladder, while they must navigate a urethral canal four times as long in a man.
What's a woman to do? Two very easy steps are ensuring cleanliness and minimizing irritation. Be sure you and your sex partner keep your genital and anal areas clean at all times and wash your hands (and under your fingernails) before foreplay and sex. If your partner is uncircumcised, he should always clean under the foreskin before sex. A circumcision would eliminate that problem, and men do have them. If you include anal penetration in your lovemaking, be sure your partner uses a condom, discards it, and washes his penis before vaginal entry.
Vary your sexual positions, too, to avoid bruising the urethra. Keep a tube of sterile lubricant, such as K-Y Lubricating Jelly, handy. If recurring UTIs are a serious problem for you, and you think your contraception is the cause, consider changing your method.
You may also want to consider sterilization if your family is complete and you can't get rid of your UTIs after taking other preventive measures. Alternatively, your partner might consider having a vasectomy.
Pregnancy and Childbirth
The hormonal changes of pregnancy cause the muscles in the urinary system to relax. This allows urine to be retained in the ureters and bladder. Fifteen percent of pregnant women have bladder infections without even knowing it. If you get a UTI during pregnancy, it's important to treat it right away because kidney infections, dangerous enough to you, can also lead to premature ruptures of the membranes and thus premature delivery of your baby. Your doctor will know which antibiotics are safe to take during pregnancy. This is one of the reasons your doctor will ask for a urine sample during your pregnancy checkups.
Many body fluids can mix outside the body and re-enter it during the intense activity of childbirth. This, too, can lead to a UTI. In addition, the hemorrhoids that frequently disturb women after delivery provide sites for potential infection.
Menopause and Old Age
As your body ages, your bladder becomes less elastic and may not empty completely. That allows urine to collect, and create a hospitable environment for bacteria, thereby encouraging infection. Older people tend to be less active, which adds to the problem, restricting the movement of bladder muscles and thus impeding emptying. A clean, flushed bladder also requires a nutritious diet, which the elderly don't always maintain. And diabetes, which affects many parts of the body, including the urinary system, becomes more common as people age.
Other Causes of UTI
The entrance of bacteria into the urethra is not the only way a urinary tract infection can start, and plenty of people who are not sexually active get UTIs. Sometimes, a physical condition may be the cause. When it is, antibiotic treatment alone won't resolve it. Your doctor may refer you to a urologist (a specialist in the urinary tract) if he or she isn't sure of the precise cause of your symptoms.
Kidney Stones
UTIs can result from physical blockage. The most common obstacles are urinary stones (calculi)—usually called kidney stones—which send approximately 1 of every 1,000 adults to the hospital in the United States each year. Consisting mostly of calcium, and therefore as hard as a rock, these stones can be any size from tiny to large enough to fill an entire kidney.
Kidney stones travel with the urine and can be found anywhere in the urinary system. They may be painless or excruciating, depending on their size, their location, and whether they are blocking the passage of urine. If a stone becomes lodged in the thin, sensitive ureter, pain is notoriously great. X-rays will show their location. You will need surgery or lithotripsy, in which the stone is “blown up” with ultrasound, if the stone is in a particularly painful or dangerous place and won't pass through the system of its own accord.
AN INVITING NOOK FOR BACTERIAL GROWTH
From its position immediately overhead, the bladder can push into the vaginal area when surgery, menopause, or multiple deliveries weaken the vaginal wall. The resulting pocket, called a cystocele, allows urine to collect, providing especially hospitable conditions for invading microorganisms.
Cystocele
Another cause of a UTI is a cystocele. When the vaginal wall next to the bladder has become weakened for any reason, the bladder can protrude directly into the vagina, holding back small pools of urine. Such tissue weakening is common after several vaginal deliveries, menopause, or gynecologic surgery. Cystoceles may require surgery themselves.
Diverticula
Diverticula are crevices (abscesses) that develop on the inside wall of the urethra. If several of these small pockets merge to form a larger one, urinary debris can accumulate in it. When diverticula become swollen or inflamed, urine may not drain well, leading to chronic infection. Surgery may be required. Suspect diverticula if you feel burning on urination between bladder infections.
Urethral Stenosis
A narrowing of the urethra, called urethral stenosis, can be present at birth or result from a number of conditions or activities. These include having had a UTI in childhood; infection of the vagina or vulva; previous infection, such as gonorrhea; a sudden increase in your sex life; childbirth; catheterization after surgery; the physical changes of pregnancy; and changes related to a deficiency of estrogen during and after menopause.
Related Conditions
Pain on urination is not always caused by a UTI. While the conditions described below are rare, your doctor may want to make sure they are not the problem before treating you for a repeat UTI.
Interstitial Cystitis
A condition caused by scarring or ulcers in the bladder lining is called interstitial cystitis. When the bladder fills, the sore areas are coated with urine. Over the course of several years, these sores cause the bladder lining to disintegrate and finally, to stop functioning altogether. Researchers are looking for ways to treat this painful and frustrating condition. Two methods are currently used: inserting dimethyl sulfoxide (Rimso 50) into the bladder through a catheter, or physically stretching the bladder under anesthesia.
Bladder Cancer
This rare condition causing tumors in the bladder is more common in men than in women. Blood in the urine, frequent and painful urination, and waking at night to urinate are typical symptoms A small tumor that is not attached to the bladder wall can sometimes be removed through an instrument called a cystoscope. Inserted through the urethra, the cystoscope works like a long, thin telescope with a light at the end. However large, deeply embedded tumors usually require major surgery.
