Urine leaves the bladder through another tube, the urethra. In women, the urethra is a short tube that opens just in front of the vagina. In men, it is longer, passing through the prostate gland and then through the penis. Scientists do not know exactly what causes this disease, but research does show that some people are more likely to develop it than others. A number of factors contribute to this higher risk.
Smoking is a major risk factor.
Cigarette smokers develop bladder cancer two to three times more often than do non-smokers. Quitting smoking reduces the risk of bladder ca, lung cancer, several other types of cancer, and a number of other diseases as well. People who smoke heavily and use artificial sweeteners are more at risk that people who smoke heavily and do not use artificial sweeteners. Other factors that may slightly increase risk include living in urban areas, drinking chlorinated water, and working with certain chemicals used in the rubber and textile industries, as well as hairdressers, machinists, metal workers, printers, painters, textile workers, and truck drivers. Another possible cause of bladder cancer is exposure to a parasite called Schistosoma haemotobium, found in South America, Africa, and Asia.