| Urinary tract infection is caused by direct invasion of bacteria (very seldom caused by fungus, protozoon and virus).It can be classified as upper urinary tract infection and lower urinary tract infection. Upper urinary tract infection is referring to pyelonephritis, and lower urinary tract infection includes urethritis and cystitis .Furthermore, pyelonephritis can be classified as acute pyelonephritis and chronic pyelonephritis. Women are prone to suffering from urinary tract infection. |