Urinary Tract Infections Causes

Bacteria entering the urinary tract from the urethra account for most urinary tract infection causes. The most common bacterium responsible is Escherichia coli, or E. coli, which is normally present in the colon. The proximity of the opening of the urethra to the anus allows bacteria to gain entrance to the urinary tract where they can then multiply. Bacteria traveling up the urethra is one of the leading causes of bladder infections.

Other bacterial urinary tract infection causes are Chlamydia and Mycoplasma. These two bacteria rarely enter the bladder, but are common causes of urethritis. Both can be transmitted sexually, so medical treatment for both partners is required to prevent recurrence.

In some cases, bacteria can travel from the bladder to the kidneys. Bacteria can also enter the kidneys through the blood stream. Kidney infection symptoms should never be ignored: untreated kidney infections can damage and scar the kidneys. Kidney infection symptoms are similar to bladder infection symptoms, but can also include high fevers, back pain, nausea and vomiting.

Another source of urinary tract infection causes is catheters, both those used in the home for incontinence and in the hospital during or after a medical or surgical procedure. Despite precautions bacteria can still be introduced with the catheter and thus gain entrance to the urinary tract. Diabetes increases the chances of developing urinary tract infections, as does any disease that lowers the body’s immune system.

Causes of Bladder Infections

Bacteria, typically E. coli, that manage to migrate up the urethra into the bladder are a common cause of bladder infections. Bladder stones can also be a source of bacteria, as can a diseased prostate.

In addition to being sources of bacteria, urinary tract obstructions caused by enlarged prostates and bladder stones can result in urine pooling in the bladder instead of being voided. This creates an ideal environment for bacteria to flourish. Certain types of incontinence can also cause urine to pool in the bladder, making infections more likely.

Sexual Intercourse and Urinary Tract Infections in Women

Several factors increase the likelihood of urinary tract infections in sexually active women. Friction during intercourse helps bacteria travel up the urethra, where it can become one of the causes of bladder infections. Women are advised to urinate both before and after intercourse to help flush bacteria out of the urethra.

Women who use diaphragms experience urinary tract infections with greater frequency than women using other birth control methods. The likelihood of urinary tract infections in women is also increased by the combination of condoms and spermicidal foam.


Jones, C.L. (nd). Urethritis. Retrieved March 13, 2002, from www.findarticles.com/cf_dls/g2601/0014/2601001424/p1/article.jhtml.

National Kidney and Urologic Diseases Information Clearinghouse. (updated 2001). Urinary tract infections in adults. Retrieved March 13, 2002, from www.niddk.nih.gov/health/urolog/pubs/utiadult/utiadult.htm.

Rowland, B. (nd). Kidney infections. Retrieved March 13, 2002, from www.findarticles.com/cf_dls/g2603/ 0000/2603000073/p1/article.jhtml?term=kidney infections.

urologychannel.com. (updated 2002). Urinary tract infections.Retrieved March 13, 2002, from www.urologychannel.com/uti/index.shtml.