What Causes Bladder Cancer?

We don't know all of the causes of bladder cancer, but there are certain things (known as risk factors) that can increase the chance of cancer developing.


Cigarette, cigar, and pipe smoking increases your risk of bladder cancer. In fact, half of all bladder cancer cases in the United States are caused by cigarette smoke. Bladder cancer develops in smokers 2 to 3 times more than in nonsmokers.

When you smoke, you inhale chemicals from the tobacco. The chemicals move from your lungs into your blood. Your kidneys filter the chemicals out of your blood and send them to your bladder. Over time, these chemicals can damage the cells that line the inside of your bladder. This damage increases the chance of cancer developing.

Chemicals in the Workplace

Long-term exposure to chemicals used to make plastics, paints, textiles, leather and rubber may also cause bladder cancer. Hairdressers, machinists, printers, painters and truck drivers may be at risk for bladder cancer. Chemicals may cause about 23 out of every 100 bladder cancer cases. Like the chemicals in cigarette smoke, these chemicals (carcinogens) can remain in the bladder for a few hours before you urinate. In that way, the bladder becomes a place where cancer can develop.

Other Risk Factors

  • Frequent or long lasting bladder infections
  • Certain drugs for other cancers, such as cyclophosphamide (Cytoxan®)
  • Radiation therapy in the pelvic area, such as for cervical cancer or prostate cancer
  • High levels of arsenic in drinking water

More than 90% of all bladder cancers begin in the inner lining of the bladder (urothelium). Most tumors in the bladder stay in this area or in the next layer (the lamina propria) and don't move into the bladder muscle.