A urinary tract infection (UTI) is an infection occurring in the kidneys, ureters, bladder, or urethra. It is a fairly common infection, especially in women. In most cases, it is caused by Escherichia coli (E. coli) bacteria. Risk factors include urinary tract problems (such as kidney stones), sexual intercourse, and menopause. Symptoms include a frequent urge to urinate, a burning feeling in the area of the bladder or urethra during urination, and milky or cloudy urine. A UTI is treated with antibiotics.
What Is a UTI?
A urinary tract infection (UTI) is a serious health problem that affects millions of people each year. Urinary tract infections are the second most common type of infection in the body, and they account for about 8.3 million doctor visits each year. Urinary tract infections are more common in women than men, and 1 out of 5 women will develop a urinary tract infection during their lifetime. Although urinary tract infections in men are not as common, they can be very serious when they occur (see UTI in Men for more information).
Understanding the Urinary System
The urinary system consists of the kidneys, ureters, bladder, and urethra.
- Remove excess liquid and wastes from the blood in the form of urine
- Keep a stable balance of salts and other substances in the blood
- Produce a hormone that aids the formation of red blood cells.
Narrow tubes called ureters carry urine from the kidneys to the bladder, a sack-like organ in the lower abdomen. Urine is stored in the bladder and emptied through the urethra.
The average adult passes about a quart and a half of urine each day. The amount of urine varies, depending on the fluids and foods a person consumes.