Bladder cancer is the result of cell changes in the mucous (inside) wall of the bladder. It is caused by changes in the cells' chromosomes or DNA (deoxyribonucleic acid).

This form of cancer develops most often in people between the ages of 60 and 79, with the average age being 67. The disease is three times more common in men than in women. It is one of the most common forms of cancer to strike men.

Generally the first sign is blood in the urine. It may be visible or the amount may be so small that it can only be discovered by chemical testing ('stix' test).

There does not need to be blood in the urine constantly. In fact, there are often periods in which there is no evidence of blood at all. So one should not be fooled by a symptom that seems to have gone away.

There may be frequent urination, stinging and pain across the pubic bone or exactly the same symptoms as in an ordinary bladder infection.

If you think you're at risk of bladder cancer, discuss your concerns with your doctor. He or she may be able to suggest ways to reduce your risk. Also, keep in mind that having one or more risk factors doesn't mean you'll develop the disease. In general, the following factors may increase the likelihood that you'll develop bladder cancer:

• Smoking. Smoking is the single greatest known cause of bladder cancer. The risk increases with the number of cigarettes smoked a day and the number of years you've smoked.
• Industrial chemicals. Repeated exposure to chemicals used in the manufacture of dyes, rubber, leather, textiles and paint products may increase your risk of developing bladder cancer years later.
• Age. The chance of getting bladder cancer increases as you grow older. The average age at diagnosis is 68 or 69. People younger than 40 rarely get the disease.
• Race. Caucasians are twice as likely to develop bladder cancer as blacks and Hispanics are. Asians have the lowest rates of the disease.
• Sex. Men are two to three times more likely to get bladder cancer than are women.
• Certain drugs. Treatment with certain anti-cancer drugs increases your risk of bladder cancer.
• Chronic bladder inflammation. Chronic or repeated urinary infections or inflammations may increase your risk of a certain form of bladder cancer. But doctors don't believe infection or inflammation alone causes cancer.
• Family history. You're at higher risk of bladder cancer if you have family members with the disease.
• Personal history. Having bladder cancer once makes it more likely you'll get it again. Tumors may recur in your ureters or urethra as well as in the bladder itself.