Normal urine is sterile. It contains fluids, salts, and waste products, but not bacteria, viruses, or fungi. A bladder infection (also called cystitis) occurs when microorganisms, such as bacteria from the digestive tract, cling to the opening of the urethra and begin to multiply and irritate the lining of the urinary system.

Bladder infections are generally much less common in men than in women. This is because men have a longer urethras (the tube that drains urine from the bladder). This makes it more difficult for bacteria to reach the bladder and cause infection. Although urinary tract infections in men are not common, they can be very serious.

When small amounts of urine remain in the bladder, this creates a perfect environment for bacteria to multiply and cause infection. In men, this poor emptying of the bladder is often due to an enlarged prostate, called benign prostatic hypertrophy (BPH). Because BPH commonly develops as men age, bladder infections occur more frequently in men over the age of 50.

Other risk factors of bladder infections in men include:

• Having a catheter (a tube) inserted to drain urine from the body (eg, due to a recent illness or surgery)
• Having diabetes or a condition that affects your immune system
• Having another condition that affects the urinary tract (eg, kidney stones, bladder stones, urethral stricture, neurogenic bladder, prostate cancer)

The symptoms of bladder infection vary from person to person and can range from mild to severe. Symptoms may include:

• Frequent and urgent need to urinate
• Passing only small amounts of urine
• Pain in the abdomen, pelvic area, or lower back
• Burning sensation during urination
• Leaking urine
• Increased need to get up at night to urinate
• Cloudy, bad-smelling urine
• Blood in the urine
• Low-grade fever
• Fatigue

If the infection is severe enough to inflame the bladder wall, it may also cause blood in the urine and leave it looking cloudy. If you have symptoms of a bladder infection, it is important for you to see your doctor so that she can treat you.

Treatment typically involves taking an antibiotic for two weeks. Most men feel better within a few days of beginning the antibiotic. It is important to take the full course of antibiotics prescribed to make sure the infection is completely treated. Your doctor may recommend further testing if you have other symptoms, like a fever and a recurrent infection.

Certain conditions have similar symptoms to those of a bladder infection. If you have recurring infections or if no infection can be found, your doctor may look for one of the following conditions:

• Urethritis—may be either inflammation or infection of the urethra
• Urinary stones—can sometimes develop in the bladder causing irritation and infection
• Bladder tumors
• Prostatitis (inflammation or infection of the prostate gland)
• Urethral stricture (narrowing of the urethra)