A urinary tract infection, also called a UTI, is an infection that occurs in the urinary system. This includes the bladder, ureters, and kidneys. Most infections involve the bladder, which is known as the lower urinary tract. UTI is the most common infection in the U.S. for women, with about 40% of women experiencing at least one UTI in their lifetimes.

UTIs can occur anywhere in the urinary tract. The most common places are the bladder (where urine is stored) and the urethra (the tube through which you urinate). Less common but more serious is an infection of the kidneys, which filter waste and extra water from the blood to make urine. Infections may be triggered by sexual activity, catheters, and other factors.

A urinary tract infection usually causes one or more of the following symptoms: Unusually frequent urination, an intense urge to urinate, pain, discomfort, or a burning sensation during urination, awakening from sleep to pass urine, and pain, pressure, or tenderness in the area of the bladder (in the middle of the lower abdomen below the navel).

Types of Urinary Tract Infection: Urinary tract infections are caused by bacteria that invade the urinary epithelium cells, causing irritation and inflammation. The infection can start in the urethra and progress its way up to the bladder, ureters, or kidney. Infection of the urethra or bladder is known as a lower urinary tract infection.

What causes urinary tract infections? Normal urine is sterile and contains fluids, salts, and waste products. It does not contain bacteria, viruses, or fungi. A UTI happens when germs, most often bacteria from the digestive tract, get into the opening of the urethra and start to multiply. Symptoms may include fever and urine that looks dark, cloudy, or reddish in color.

Prevention tips include staying hydrated, as this helps keep bladder tissue healthy. It also dilutes your urine and lowers the concentration of bacteria in the bladder. Some people can clear an infection on their own just by drinking fluids. It’s recommended to drink at least 50 ounces or about 1.5 liters of fluid daily to prevent infections.

A UTI occurs in part of the urinary system, which includes the urethra, bladder, ureters, and kidneys. Nearly all UTIs are bacterial, most frequently caused by Escherichia coli, which normally plays a vital role in keeping the digestive system healthy but can cause infection if it enters the urinary tract. Smaller numbers of UTIs may be caused by other factors.

For more in-depth information, visit these sources:
Mayo Clinic Health System
Harvard Health
Harvard Health
U.OSU
University of Rochester Medical Center
Mayo Clinic Health System
Harvard Health