Q: What are bladder polyps, and why do they develop?

A: Bladder polyps are growths in the lining of the bladder. They may cause bleeding, but commonly they don't cause any symptoms. In some cases, bladder polyps cause painful or frequent urination. Because such growths can be cancerous, doctors usually recommend removing them with surgery.

The cause of most benign and cancerous bladder polyps is unknown. Risk factors include smoking and being exposed to industrial chemicals. Men are affected more often than women. Bladder cancer is unusual in adults under age 55. A parasitic infection (called Schistosomiasis) can cause bladder polyps (and an increased risk of bladder cancer) when the parasite eggs accumulate in the wall of the bladder. This infection is more common in developing countries, such as parts of Africa, South America, and the Caribbean.

Bladder polyps are most commonly discovered when a person has blood in the urine. The person either sees the urine has turned red or the doctor tests the urine and finds red blood cells.

A cystoscopy is the most useful test to detect bladder polyps. With a cystoscopy, a doctor inserts a device through the urethra (the opening through which you urinate) into your bladder. This allows the doctor to inspect the lining of your bladder. During a cystoscopy, the doctor may remove a tissue sample for a biopsy or remove a polyp.

Benign bladder polyps may require removal to confirm they are not cancerous and to prevent bleeding or other urinary symptoms. Early detection and treatment of cancerous bladder polyps are associated with the best outcomes. So, if you see blood in your urine, if urine tests repeatedly show microscopic amounts of blood in the urine, or if you have urinary symptoms (such as frequent or painful urination), see your doctor for evaluation.