Risks and causes of bladder cancer

Smoking tobacco is the biggest cause of preventable bladder cancer in the UK. There are some other risk factors that can increase your risk of developing bladder cancer.

Anything that can increase your risk of getting a disease is called a risk factor. Different cancers have different risk factors. Having one or more of these risk factors doesn't mean you will definitely get that cancer.

Risk factors

Risk factors for bladder cancer include:

Smoking

Smoking cigarettes increases the risk of bladder cancer. Around half of all bladder cancers are caused by smoking. 

Your risk of getting bladder cancer if you smoke is up to 4 times that of someone who has never smoked. People with the highest risk are those who:

• smoke heavily
• started smoking at a young age and continue to smoke for a long time
• have smoked for a long time

Smoking other types of tobacco products like cigars and pipes also increases your risk.

How smoking may increase your risk

Chemicals in the smoke get into the bloodstream. They are then filtered out of the blood by the kidneys and end up in the urine. When the urine is stored in the bladder, these chemicals are in contact with the bladder lining.

Chemicals called arylamines are known to cause bladder cancer. Arylamines in cigarette smoke may be the cause of the increased risk.

Chemicals at work

If you have been diagnosed with bladder cancer, it's worth talking to your urologist or cancer doctor to find out if it could be linked to chemicals in your workplace. 

Certain types of jobs can carry higher risk than others, depending on the exposures people have in their jobs. But nowadays, if people are exposed to dangerous chemicals there are regulations to keep workers’ exposure within safety limits.

Aromatic amines

This is a group of chemicals known to cause bladder cancer. Some of these chemicals have been banned in the UK for over 50 years. But you may have been exposed to them if you work in industries that produce dyes, rubber or textiles. It can take around 30 to 40 years or more for a bladder cancer to develop.

Polycyclic aromatic hydrocarbons (PAH)

These are a group of chemicals that might increase the risk of bladder cancer. You may have been exposed to them if you have worked in:

• industries where people handle carbon or crude oil, or substances made from them
• any industry involving combustion, such as smelting

Employers have a legal duty to protect the health and safety of their employees under law. If you have a diagnosis of bladder cancer and know that you have been exposed to any of these chemicals at work, you may be able to claim an allowance from the government. This is called an Industrial Injuries Disablement Benefit from the Department for Work and Pensions. Discuss this with your doctor.

Infections

An infection called schistosomiasis (bilharzia) increases the risk of bladder cancer. The infection is caused by a parasitic worm that lives in fresh water in some parts of the world including Africa and Asia. But this parasitic infection is extremely rare in the UK.

Some studies have also found a link between bladder cancer and bladder stones.

Urinary catheters 

A research study found that having a catheter in for a long time might increases your risk of bladder cancer compared with the general population. The study found that your risk might increases if you're over the age of 45 and under the age of 60 years old. This is compared to the general population of the same age.

Previous radiotherapy for cancer

Your risk of developing bladder cancer is higher if you have had radiotherapy to treat cancers in your pelvis. For example, prostate cancer.

Other medical conditions

Diabetes

Many studies have looked for a link between diabetes and bladder cancer. The results have been varied. Researchers think that if there is a link, it is likely to be due to a drug used for diabetes called pioglitazone. Some studies show this drug increases the risk of bladder cancer.

Family history

You might have a slight increase in risk of bladder cancer if you have a first degree relative with bladder cancer. First degree means a parent, child, sister or brother. This might be because you share certain behaviours such as smoking, which increases your risk.

Being overweight

Some research has shown that you may be at an increased risk of getting bladder cancer if you're obese. But more research is needed and it's unclear how much of an increased risk there may be. 

Other possible causes

There are often stories about potential causes in the media. It isn’t always clear which ideas are supported by evidence. There might be things you have heard of that we haven’t included here. This is because either there is no evidence about them or it is less clear.

More information on risk factors for bladder cancer

We have more detailed information for health professionals about bladder cancer risks and causes.