A urinary tract infection (UTI) is caused when bacteria enter the urethra and spread throughout the urinary system. The urinary tract actually includes the kidneys, the ureters, the bladder and the urethra, although infections of specific organs are given individual names. Infections will usually start in the urethra and the bladder and then move on to the ureters and kidneys, so it's important to get UTIs treated promptly before they become more serious.
Urinary tract infections are more common in women, and while the exact reason isn't known, it's most likely due to the relative shortness of the female urethra and the urethra's closeness to the vaginal and anal openings, allowing cross-contamination.
Anyone who has to use a catheter for an extended period of time is also at risk for a urinary tract infection. Even though catheters are sterilized, they provide an easy means for bacteria to enter the urinary tract.
Obstructions in the urinary tract, such as kidney stones, conditions that don't allow the bladder to completely empty, and some congenital defects all have the potential to cause UTIs by introducing bacteria to the system. Any disease that weakens the immune system can cause urinary tract infections by making bacteria more difficult to fight. In males, being uncircumcised is also a potential breeding ground for bacteria.
The symptoms of a urinary tract infection vary from person to person. The urge to urinate frequently is common, although they may actually produce little urine at any given time. There may also be a burning pain while urinating and a milky, cloudy or reddish tint to the urine. There may be pressure in the pelvic area. People with a UTI may also have more generic symptoms, such as feeling tired and worn out or having a fever. A fever, along with nausea, vomiting and a pain in the back or under the ribs, may mean that the infection has become more severe and spread to the kidneys.
A doctor will test for a urinary tract infection through urinalysis, and an infection can typically be treated with antibiotics. If you suspect that you may have a UTI, you should visit your doctor immediately.