Urinary tract infections are common disorders resulting from microbial invasion of the urinary system. The microorganisms involved may be bacteria, chlamydia, viruses, fungi, or parasites. Cystitis is a painful but usually curable infection of the lower urinary tract. Urinary tract infections also include pyelonephritis, an infection of the kidneys. Frequently this may be the result of an untreated or undiagnosed bladder infection. Inadequate treatment of this infection may occasionally result in permanent kidney damage and/or a potentially life-threatening infection of the blood.
For anatomical reasons (particularly their shorter urethra), women are 10 times more likely than men to suffer from this infection. More than a half of adult women experience urinary tract infections at some time. Urinary tract infections occur in 8.5 million women in the USA each year, and in many millions more women elsewhere.