Describing an Infection

The kidneys produce urine while filtering blood. The urine then travels through the ureters to the bladder for temporary storage. The bladder is emptied during urination, during which the urine travels through the urethra, a tube connecting the bladder to your skin. Based on the number of reported doctor visits, an estimated 8-10 million urinary tract infections occur each year.

Under normal circumstances, urine is sterile, meaning that it contains no bacteria. When bacteria get into the urine and start to grow, an infection develops. Escherichia coli (E. coli) is the cause of approximately 80% of bladder infections. These bacteria typically live in the colon and rectal area. Hygiene issues, sexual activity, hormonal changes, and occasionally anatomical abnormalities can allow these bacteria to migrate towards the urethra's opening and up through that channel to the bladder. Other bacteria that sometimes cause urinary tract infections include Staphylococcus saprophyticus (5-10%), Klebsiella pneumoniae, Proteus mirabilis, Enterococcus sp., Pseudomonas aeruginosa, Chlamydia trachomatis, and Mycoplasma hominis.

There are several names which are used to describe an infection of the lower urinary tract. “UTI,” “bladder infection,” and “cystitis” are often used interchangeably, since they all mean the same thing.

RISK FACTORS:

• Statistically men experience fewer of these infections because their urethra is much longer, and therefore the bacteria have a significantly greater distance to travel to reach the bladder.
• Sexual contact increases risk because it can put nearby bacteria in closer proximity to the urethra.
Urinating after sexual contact reduces this risk by flushing out bacteria in the urethra.
• Any condition that leads to incomplete emptying of the bladder (urine retention) increases risk.
• Structural abnormalities (like bladder prolapse or diverticulum) or blockages (like BPH or kidney stones) can increase risk because of the limits they may impose on flushing out bacteria during urination.
• Immune system suppressing medications and diseases (such as diabetes) create an increased risk in resisting an infection.
• Any object inserted into the urethra (catheter, jewelry, etc.) can carry unwanted bacteria into the urethra.
• The use of a diaphragm or condoms with spermicidal foam puts women at higher risk.
• The protective effects of estrogen against urinary infection are lost after menopause.