A risk factor is something that increases your chances of getting a disease or condition.

It is possible to develop bladder cancer with or without the risk factors listed below. However, the more risk factors you have, the greater your likelihood of developing bladder cancer. If you have a number of risk factors, ask your doctor about reducing your risk.

Some factors cannot be altered. Bladder cancer is nearly 3 times more common in men than women. The risk of bladder cancer also increases with age. Incidence rises sharply after age 55. Certain genetic factors or family history may increase the risk of bladder cancer:

  • Specific genetic mutations that affect cell DNA. These mutations can program cells to grow without control. Some genes do not break down toxins, which allow them to build up in the bladder, increasing irritation.
  • Family history of bladder or other cancers.
  • Structural birth defects of the bladder or urinary tract.

Other factors that can increase the risk of bladder cancer include:


Smoking is the biggest risk factor, accounting for nearly half of all bladder cancers. Smoke and carcinogens (cancer-causing agents) enter the bloodstream after being inhaled. These agents affect every cell in the body and are eventually processed like normal waste. The kidneys filter the agents from the blood and pass them into the bladder where it is held until urination. As a result, the bladder walls are regularly exposed to concentrated levels of the carcinogenic agents. The carcinogens irritate and damage the cells that line the inside of the bladder, increasing the chance of cancerous cells.

Occupational Exposure

Exposure to certain chemicals greatly increases a person’s risk of bladder cancer. Occupations with highest exposure to such cancer-causing agents include:

  • Painting
  • Dye, leather, paper, rubber, and metal industries
  • Barbers and beauticians
  • Plumbers
  • People working with dry-cleaning chemicals
  • Tar and asphalt workers
  • Truck drivers

Bladder Irritation and Infection

Cancer is more likely to develop in areas with inflammation and/or regular injury because of rapid cell changes. There are a number of conditions that cause bladder irritation over a long period of time:

  • Bladder stones—A buildup of minerals in the bladder can cause stones. Some stones travel from the kidney. If they do not cause symptoms, retained bladder stones can cause inflammation and irritation in the bladder.
  • Infections cause bladder irritation. If infections are left untreated or come back frequently, the recurrent inflammation may increase your risk of bladder cancer. This may include bacterial or fungal infections, as well as sexually transmitted diseases.
  • In rare cases, a parasite that lives in the bladder. Infection with certain parasites that live in the bladder are associated with increased risk of a specific type of bladder cancer. Though very rare in the United States, it is common in tropical regions of the world.
  • Previous bladder cancer—Previous procedures and treatments irritate the bladder. Recurrence of bladder cancer is common.

Medical Treatment

All medical treatments have some degree of risk, and some may increase your risk of certain cancers. Doctors weigh the risk for treatments to the benefits that they provide. Some treatments that may increase the risk of bladder cancer include:

  • Long-term use of a bladder catheter—A bladder catheter is a tube used to drain the bladder of urine when the bladder is not able to do so normally. Catheters left in for long periods of time increase irritation and can lead to infection.
  • Cyclophosphamide, a chemotherapy drug used to treat cancers and autoimmune disorders. This drug is toxic to the bladder.
  • Radiation therapy to the pelvic region. Treatment for cervical or ovarian cancer may include radiation aimed at the pelvis. This may cause damage to the bladder, which is adjacent to these structures.
  • Taking pioglitazone for more than one year is associated with a high risk of bladder cancer. This medication is used to treat type 2 diabetes. If you take this drug, talk to your doctor about alternative medications.


A review of 15 studies suggest obesity is associated with an increased risk of bladder cancer when compared to people who have a normal weight. The specific reason for the association is unclear, but obesity is also a risk factor for other types of cancer. It may be related to the body's reaction to excess weight, which may cause inflammation, hormone imbalances, or immune system problems. The higher the weight increase, the higher the risk of bladder cancer.

Regular Low Fluid Intake

Dehydration decreases the amount of fluid in the body. As a result, there is a higher concentration of carcinogens in the urine as it sits in the bladder. Increasing fluid intake can decrease the concentration of carcinogens and encourage more frequent urination to pass harmful substances out of the body. Medical guidelines often encourage drinking fluids with certain procedures to help flush medications, dyes, or other harmful materials from the body.