When functioning properly, the urinary tract is a marvel of efficiency. Throughout every 24-hour period, it thoroughly cleanses approximately 200 quarts of fluid, returning most of it to the circulatory system and eliminating the remaining two quarts as urine through the bladder.

As with most parts of the body, however, when this system breaks down, it causes pain and discomfort. And unfortunately, it breaks down quite frequently. Urinary tract infections (UTIs), second only to respiratory infections in frequency, account for 10 million visits to the doctor each year. One in five women will suffer from cystitis, an inflammation of the bladder, at some time in her life. Twenty to 30 percent of women who have a UTI will have a second infection, and 30 percent of those will have yet another. In addition, at least 13 million adults suffer from urinary incontinence (an inability to hold urine) to some degree.

Some Facts About Urinary Tract Disorders

• Women are more prone to UTIs than are men or children.

• Urinary tract problems increase with menopause.

• An estimated 3 percent of girls and 1 percent of boys have had a UTI by age 11.

• Young children have the greatest risk of kidney damage caused by urinary tract infections.

• Certain people who contract one or more urinary tract infections may need further testing to ensure they do not suffer from other health problems.

The kidneys, ureters, bladder, and urethra are the key components of the urinary tract. The kidneys filter waste from the blood and eliminate it in the form of urine. The urine travels from the kidneys to the bladder through narrow tubes called ureters. The bladder, a ball-shaped receptacle in the lower abdomen, stores the urine for anywhere from one to eight hours before it is emptied from the body through the urethra.

Tracing the Course of the Urinary Tract Originating at the kidneys, the urinary tract conducts waste fluid down the ureters and into the bladder, where it accumulates until expelled through the urethra. Note the striking difference in the lengths of the male and female urethras. This, more than any other factor, accounts for a woman's greater vulnerability to bladder infections.