RELATED STORIES • Bladder infections: Can men get them too?

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Cystitis is an inflammation or infection of the urinary bladder. When caused by germs, cystitis is called a bacterial urinary tract infection (UTI). UTIs can be painful and annoying. A UTI such as cystitis can become a serious health problem if the infection spreads to your kidneys.

Cystitis usually begins when bacteria enter the urinary tract through the urethra, the tube through which urine exits your body. From there, bacteria adhere to the bladder wall, and begin to multiply. Less commonly, bacteria can spread to the bladder from an infection in another part of the body.

The usual treatment for cystitis is antibiotics. You can take a number of steps to help prevent cystitis and other UTIs.

Most people with bladder infections develop signs and symptoms. These may include:

• A strong, persistent urge to urinate
• A burning sensation when urinating
• Passing frequent, small amounts of urine
• Blood in the urine (hematuria)
• Passing cloudy or strong-smelling urine
• A feeling of pressure in the lower abdomen
• Low-grade fever

In young children, new episodes of bed-wetting (enuresis) may also be a sign of a UTI.

Your urinary system is composed of the kidneys, ureters, bladder and urethra. All play a role in removing waste from your body. Your kidneys, a pair of bean-shaped organs in your upper-posterior abdomen, filter waste from your blood and adjust the body composition of many substances. Tubes called ureters carry urine from your kidneys to the bladder, where it is stored until it exits your body through the urethra.

UTIs typically occur when bacteria enter the urinary tract through the urethra and begin to multiply. The urinary system is designed to keep out such microscopic invaders. The bladder secretes a protective coating that prevents bacteria from attaching to its wall. Urine also has antibacterial properties that inhibit the growth of bacteria. However, certain factors increase the chances that bacteria will take hold and multiply into a full-blown infection.

Sometimes cystitis is referred to as honeymoon cystitis, because this bladder infection commonly occurs in women as a result of sexual intercourse. During sexual activity, bacteria may be introduced into the bladder through the urethra. But even sexually inactive girls and women are susceptible to lower urinary tract infections because the female genital area often harbors bacteria that can cause cystitis.

Most cases of cystitis are caused by Escherichia coli (E. coli), a species of bacteria commonly found in the genital area. A new strain of antibiotic-resistant E. coli may be the cause of increasingly hard-to-treat UTIs in women.

Although more rare, other causes of cystitis, or conditions that may mimic bacterial UTIs, include:

• Tuberculosis or yeast infection (vaginitis)
• Radiation treatment to the bladder area
• Tumors in the bladder
• Interstitial cystitis
• Certain medications

Two main types of infections
The two main types of bladder infections are:

• Community-acquired bladder infections. These infections occur when people who aren't in a medical care facility, such as a hospital or nursing home, develop a bladder infection. This condition is common in women between the ages of 30 and 50, but it is rare in men of the same age. However, men older than 50 may be at risk of this type of infection because of prostate enlargement, a common condition that can block urine flow in older men.
• Hospital-acquired, or nosocomial (nos-o-KO-me-ul), bladder infections. These infections occur in people in a medical care facility, such as a hospital or nursing home. Most often they occur in those who have had a urinary catheter placed through the urethra and into the bladder to collect urine, a common practice before some surgical procedures, for some diagnostic tests, or as a means of urinary drainage for elderly people or people confined to bed. Nosocomial bladder infections can occur when a temporary or permanent catheter is placed in the bladder of a person who is unable to void spontaneously.

Some people are more likely than are others to develop bladder infections or recurrent urinary tract infections. Women are one such group. Up to 20 percent will develop a bladder infection over a lifetime. A key reason is anatomy. Women have a shorter urethra than men have, which cuts down on the distance bacteria must travel to reach the bladder.

Women who are sexually active tend to have more UTIs, because sexual intercourse can result in bacteria being pushed into the urethra. Women who use diaphragms for birth control also may be at higher risk. Hormonal changes during pregnancy may increase the risk of a bladder infection as well.

Other risk factors in both men and women include:

• Interference with the flow of urine. This can occur in conditions such as an enlarged prostate or a stone in the bladder.
• Changes in the immune system. This can occur with conditions such as diabetes, increasing the risk of UTIs.
• Prolonged use of bladder catheters. These tubes may be needed in people with chronic illnesses or in older adults.

Research funded by the National Institutes of Health suggests that a woman's blood type may play a role in her risk of recurrent infections of the bladder and urinary tract. Bacteria may be able to attach to cells in the urinary tract more easily in those with certain blood factors. But more research is needed to determine whether an association exists and whether it could be useful in identifying people at risk of recurrent infection.

If you have symptoms of a bladder infection, talk to your doctor as soon as possible. If your doctor suspects you have a bladder infection, he or she may ask for a urine sample to determine whether bacteria, blood or pus is in your urine.

When treated promptly and properly, UTIs rarely lead to complications. But left untreated, a urinary tract infection can become something more serious.

An untreated bladder infection can lead to potentially serious complications, such as a kidney infection (pyelonephritis), which could be associated with a bacterial bloodstream infection (bacteremia). Also, kidney infections may permanently damage your kidneys. Young children and older adults are at the greatest risk of kidney damage due to bladder infections, because their symptoms are often overlooked or mistaken for other conditions.

Treating community-acquired infections
Antibiotics are the first line of treatment for community-acquired bladder infections. Which drugs are used and for how long depend on your overall health and the bacteria found in your urine. The medications most commonly recommended for simple UTIs include amoxicillin (Amoxil, Trimox), ciprofloxacin (Cipro), nitrofurantoin (Furadantin, Macrodantin), sulfamethoxazole-trimethoprim (Bactrim, Septra) and trimethoprim (Proloprim, Trimpex). Make sure your doctor is aware of any other medications you're taking or any allergies you might have.

Usually symptoms clear up within a few days of treatment. However, you'll likely need to take antibiotics for three days to a week, depending on the severity of your infection. No matter what the length of treatment, take the entire course of antibiotics recommended by your doctor to ensure that the infection is completely eradicated.

If you have recurrent UTIs, your doctor may recommend longer antibiotic treatment or refer you to a doctor who specializes in urinary disorders (urologist) or a doctor whose specialty is kidneys (nephrologist) for an evaluation to see if urologic abnormalities may be causing the infections. For some women, taking a single dose of an antibiotic after sexual intercourse may be helpful.

Treating hospital-acquired infections
Hospital-acquired bladder infections can be a challenge to treat because bacteria found in hospitals are often resistant to the common types of antibiotics used to treat community-acquired bladder infections. For that reason, different types of antibiotics and different treatment approaches may be needed. Currently, researchers are testing whether using catheters pre-treated with antimicrobial products may help reduce the incidence of this type of bladder infection. Research is underway to investigate the development of vaccines that might prevent cystitis and decrease the need for frequent antibiotic use.

You can take steps to reduce the risk of bladder infections. Women, in particular, may benefit from the following:

• Drink plenty of liquids, especially water. Cranberry juice may have infection-fighting properties. However, don't drink cranberry juice if you're taking the blood-thinning medication warfarin (Coumadin). Possible interactions between cranberry juice and warfarin can lead to bleeding.
• Urinate frequently. Avoid retaining your urine for a long time when you feel the urge to void.
• Wipe from front to back after a bowel movement. Doing so prevents bacteria in the anal region from spreading to the vagina and urethra.
• Take showers rather than tub baths. If you're susceptible to infections, doing so can help prevent infections.
• Gently wash the skin around the vagina and anus. Do this daily, but don't use harsh soaps or wash too vigorously. The delicate skin around these areas can become irritated.
• Empty your bladder as soon as possible after intercourse. Drink a full glass of water to help flush bacteria.
• Avoid using deodorant sprays or feminine products in the genital area. These products can irritate the urethra.

Cystitis can be painful, but you can take steps to ease your discomfort until antibiotics clear the infection. Sometimes a heating pad placed over your lower abdomen can help minimize feelings of bladder pressure or pain. Drink plenty of fluids, but avoid coffee, alcohol, soft drinks with caffeine, citrus juices and spicy foods until your infection has cleared. These items can irritate your bladder and aggravate your frequent or urgent need to urinate. It also may be helpful to sit in a bathtub of warm water for 15 to 20 minutes.

If you have recurrent bladder infections, let your doctor know. Together, you can develop a strategy to reduce recurrences and the discomfort that cystitis can bring.