Risks and causes of kidney cancer
We don't know what causes most kidney cancers. But some factors may increase the risk of getting it. These include getting older, smoking and some rare inherited conditions.
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.
Age and gender
Kidney cancer is more common in older people. Around 35 in 100 kidney cancers (around 35%) develop in people aged 75 and over.
Men are more likely to develop kidney cancer than women.
Being overweight or obese
Being overweight or very overweight (obese) increases the risk of getting kidney cancer. This causes around 25 out of every 100 kidney cancers (around 25%). So around a quarter of kidney cancers. The more overweight someone is, the higher the risk.
Being overweight causes changes in hormones in the body, particularly for women. It could be these changes in hormone balance that increase the risk of kidney cancer.
Smoking
People who smoke have an increased risk of developing kidney cancer. Smoking causes almost 15 out of 100 kidney cancers (almost 15%). This risk increases with the length of time and number of cigarettes smoked.
The risk falls if you stop smoking. After 10 years it becomes nearly the same as those who have never smoked.
Exposure to ionising radiation
Exposure to high energy (ionising) radiation can increase the risk of kidney cancer. For example, having radiotherapy for some types of cancer.
Doctors make sure the benefit of having radiotherapy outweighs the small risk of developing a second cancer from radiotherapy. Radiotherapy treatment is planned very precisely and newer techniques of giving radiotherapy cause less damage to healthy tissues.
Chemicals at work
Working with certain chemicals may increase the risk of kidney cancer. For example working in the textile manufacturing industry. Or using certain chemicals to clean or degrease metal.
There is also research linking exposure to arsenic and cadmium to kidney cancer. As well as welding fumes and chemicals used in the printing process. But there is limited evidence for this.
Exposure to these kinds of chemicals is rare. If you do work with them, there are regulations in place to protect you.
Chronic kidney disease
People whose kidneys do not work very well (chronic kidney disease) have an increased risk of kidney cancer.
Kidney stones
Tiny crystals of minerals such as calcium and 
in the urine can stick together to form kidney stones.
Men who've had kidney stones have an increased risk of kidney cancer. But women who've had kidney stones don't have an increased risk.
Gene changes and inherited conditions
A few people inherit changes in their genes that increase their risk of getting kidney cancer. Cancer caused by these gene changes is called hereditary or familial kidney cancer.
Changes in a gene’s make it behave in an abnormal way. Scientists are finding out which genes carry these changes. In the future this could help doctors predict who is at risk of getting hereditary kidney cancer.
People with these genetic conditions and kidney cancer, often have it in both kidneys (bilateral kidney cancer). They may have several cancers in each kidney. They may also develop the cancer at a younger age than people with non inherited cancers.
Most of the inherited conditions are dominant genetic conditions. This means that you only have to inherit the gene changes from one parent. Even so, they are rare. People with these inherited conditions usually have screening tests to check for cancers.
Inherited conditions that increase the risk of kidney cancer include:
Von Hippel-Lindau (VHL) syndrome
This is an inherited cancer syndrome. The Von Hippel-Lindau (VHL) gene runs through affected families.
People who carry the gene have an increased risk of developing kidney cancer and cancer in the brain and spine. They also have an increased risk of very rare cancers of the adrenal gland, pancreas, and inner ear.
Tuberous sclerosis complex (TSC)
This is another condition caused by a gene change. People with tuberous sclerosis have an increased risk of kidney cysts and kidney cancer.
It can also cause skin, brain, lung and heart problems.
Birt-Hogg-Dubé syndrome
This inherited condition causes small non cancerous (benign) tumours to develop in the hair follicles of the skin, usually on the face. People who carry this gene have an increased risk of kidney cancer.
Hereditary papillary renal cell cancer
Hereditary papillary kidney cancer is caused by inherited gene changes. People who carry this gene can get multiple cancers in both kidneys.
Family history
People with a who has been diagnosed with kidney cancer have a greater risk of developing it themselves. However the risk is still small.
High blood pressure
Some research studies have found a link between high blood pressure or high blood pressure medicines and kidney cancer. The higher someone’s blood pressure, the higher the risk.
It is likely that high blood pressure is the link, rather than medicines used to treat it. High blood pressure damages the kidneys and is a known risk factor for kidney disease.
Thyroid cancer
People who have had thyroid cancer have an increased risk of kidney cancer.
This may be due to gene changes that are common to both cancers, older age or people having more tests and follow ups after their original cancer treatment. It may also be due to obesity which is a risk factor for kidney cancer and thyroid cancer.
Diabetes
Some studies have found that people with type 1 diabetes have a higher risk of kidney cancer.
The risk may be higher in people who use insulin to control their diabetes. But other diabetic medicines such as metformin or pioglitazone don't seem to increase the risk.
Mild painkillers
Researchers in America looked at the results of 20 studies across 6 countries. They found that some mild painkilling drugs are linked to increased kidney cancer risk.
Painkillers called non steroidal anti inflammatory drugs (NSAIDs) may increase the risk of kidney cancer slightly. These include ibuprofen. Although aspirin is a NSAID, it is not thought to increase the risk of kidney cancer.
Taking paracetamol may also increase the risk. But occasional or low dose use of these painkillers is unlikely to be harmful.
More information on risks factors for kidney cancer
There is more detailed information for health professionals about kidney cancer risks and causes in the Cancer Statistics section of the Cancer Research UK website.
Other possible causes
Stories about potential causes of cancer are often in the media. It isn’t always clear which ideas are supported by good evidence.
You might hear about possible causes we haven’t included here. This is because there is no evidence about them or because the evidence isn’t clear.
