The main risk factors for bladder cancer

Bladder cancer develops when cells in the bladder lining begin to grow abnormally. The most common cause is smoking—cigarettes, cigars, and pipes all increase risk because tobacco smoke passes through the bladder. People who smoke are two to three times more likely to develop bladder cancer than non-smokers.

The second major risk factor is exposure to certain chemicals in the workplace. Workers in rubber manufacturing, leather tanning, textile dyeing, and pesticide production face higher risk because these industries use chemicals called aromatic amines. Painters, machinists, and truck drivers also have elevated risk from occupational exposure over many years.

A history of chronic bladder irritation or infection can raise risk. People with repeated urinary tract infections, chronic catheter use, or a condition called schistosomiasis (a parasitic infection common in parts of Africa and the Middle East) have higher rates of bladder cancer.

Key Takeaways

  • Smoking is the single largest preventable cause of bladder cancer, accounting for roughly half of all cases in smokers.
  • Workplace exposure to chemicals used in manufacturing, dyeing, and pesticide production increases risk, especially after decades of contact.
  • Chronic bladder infections, long-term catheter use, and certain parasitic infections raise the chance of developing bladder cancer.
  • Age, sex, and family history also matter—bladder cancer is more common in older adults and men, and runs in some families.
  • Most people with risk factors never develop bladder cancer, and some people without known risk factors do.

Age, sex, and family history

Bladder cancer is far more common in older adults. The average age at diagnosis is around 70, and it is rare in people under 40. Men are diagnosed with bladder cancer about three to four times more often than women, though the reason is not fully understood—it may relate to smoking rates, occupational exposure, or biological differences in how the bladder lining responds to irritation.

Family history matters, but bladder cancer is not strongly hereditary the way some cancers are. If a parent or sibling had bladder cancer, your risk is somewhat higher than average, but most people with a family history never develop it. Genetic syndromes like Lynch syndrome (hereditary nonpolyposis colorectal cancer) do increase bladder cancer risk, but these are rare.

Radiation and previous cancer treatment

Radiation to the pelvis—whether for prostate cancer, cervical cancer, or other conditions—can damage bladder cells and raise the risk of bladder cancer years or even decades later. People treated with radiation therapy should discuss long-term monitoring with their doctor.

Certain chemotherapy drugs, particularly cyclophosphamide (used for lymphoma, breast cancer, and other conditions), also increase bladder cancer risk. The risk is dose-dependent, meaning higher cumulative doses carry greater risk. If you received this drug, your doctor may recommend periodic screening.

Chronic irritation and medical conditions

Anything that causes long-term irritation or inflammation of the bladder lining can increase risk. People with spinal cord injuries who use catheters for decades have higher rates of bladder cancer. Those with a history of bladder stones or recurrent severe infections also face elevated risk.

Schistosomiasis, a parasitic infection found mainly in parts of Africa, the Middle East, and South America, causes chronic bladder inflammation and is associated with a specific type of bladder cancer called squamous cell carcinoma. This is rare in North America and Europe but is a major cause of bladder cancer in endemic regions.

Arsenic and water contamination

Long-term exposure to arsenic in drinking water increases bladder cancer risk. This occurs in some regions where groundwater naturally contains high arsenic levels, and historically in areas with contaminated well water. People in parts of the southwestern United States, Bangladesh, Chile, and other regions with naturally high arsenic in water have documented higher rates.

The risk depends on how much arsenic you consumed and for how long. If you live in an area where arsenic in water is a concern, your local health department or water utility can test your water and recommend filtration if needed.

Obesity and diet

Obesity is associated with a modestly increased risk of bladder cancer, though the exact mechanism is not clear. Some research suggests that excess body weight may increase inflammation or alter hormone levels in ways that affect bladder cell growth.

Diet may play a small role as well. Some studies suggest that diets high in processed meat or low in fruits and vegetables are associated with higher risk, but the evidence is not as strong as it is for smoking or occupational exposure. No specific food has been proven to cause or prevent bladder cancer.

What does not cause bladder cancer

Artificial sweeteners were once suspected of increasing bladder cancer risk, but large studies have not found a clear link in humans. Caffeine and coffee do not cause bladder cancer. Drinking water itself—even in large amounts—does not cause bladder cancer unless it is contaminated with arsenic or other carcinogens.

Having a urinary tract infection or bladder problem does not cause cancer, though chronic or recurrent infections may slightly raise risk over time. A single infection poses no increased risk.

Frequently Asked Questions

If I have a risk factor, will I definitely get bladder cancer?

No. Most people with risk factors never develop bladder cancer. Even smokers—who have the highest risk—develop it at a much lower rate than non-smokers. Risk factors increase the odds, but they do not determine outcome.

Can bladder cancer run in families?

Bladder cancer is not strongly hereditary. If a close relative had it, your risk is somewhat higher than average, but most cases are not inherited. Rare genetic syndromes like Lynch syndrome do increase risk, but these account for a small fraction of bladder cancers.

Does quitting smoking reduce my risk of bladder cancer?

Yes. The longer you have been smoke-free, the lower your risk becomes. However, the risk never returns to that of someone who never smoked. Former smokers still have higher risk than lifelong non-smokers, which is why screening may be recommended depending on how long and how much you smoked.

What should I do if I have been exposed to workplace chemicals?

Tell your doctor about your occupational history, including the types of chemicals you handled and for how long. Your doctor can discuss whether monitoring or screening is appropriate based on your specific exposure and other risk factors.

Is there a screening test for bladder cancer?

There is no routine screening test recommended for people at average risk. People at high risk—such as current smokers with a long history, or those with occupational exposure—may benefit from discussion with their doctor about whether periodic urine tests or imaging make sense in their situation.