Urinary tract infections, or UTIs, begin in the urinary system, which includes the kidneys, bladder, ureters and urethra. Though any of these parts can become infected, most infections exist in the lower urinary tract, according to the Mayo Clinic. While bacteria cause UTIs, a number of factors promote infection by allowing bacteria to enter the urinary system. Treatment consists of antibiotics and preventative measures. Finding the cause of infections is significant to reducing them.
Anatomy
The urinary system normally protects the body from invading bacteria. Sometimes, however, bacteria enter through the urethra and reproduce in the bladder, which leads to an infection of the urinary tract. Infections more commonly occur in women, due to the nearness of the urethra to the anus, which allows for a shorter distance for bacteria to travel. Careful cleansing and hygiene habits can help women prevent bacteria from entering the urethra and reduce the likelihood of infection.
Sexual Intercourse
FamilyDoctor.org reports that sexual intercourse can lead to urinary tract infections in women, as bacteria are pushed into the urethra. Sexually active women who are prone to infections can take precautions to prevent recurring infections. Urinating after sex helps flush bacteria from the body. Changing birth control methods may also help, as diaphragms can cause infections by placing pressure on the bladder and making it difficult to expel urine completely.
Supressed Immune System
A suppressed immune system can impair the body's ability to fend off bacteria, increasing the occurrence of urinary tract infections. Diabetes and other diseases that suppress the immune system are examples of diseases linked to infection. Drink both cranberry juice and plenty of water to ward off infection. The Mayo Clinic notes that cranberry appears to work by preventing bacteria from sticking to cells that line the bladder. People with diabetes should look for sugar-free juice or use cranberry tablets, which are available at health food stores and pharmacies.
Vesicoureteral Reflux
Kids Health.org reports that 30 to 50 percent of children diagnosed with a urinary tract infection have vesicoureteral reflux, a congenital condition that causes the urine to back up into the ureters. Low doses of antibiotics prevent urinary tract infections when complications arise.


