Your risk of developing cancer depends on many factors. This includes things like whether you smoke and have a healthy balanced diet, as well as genetic and environmental factors.
Anything that can increase or decrease your risk of cancer is called a risk factor.
We don't know what causes most cases of chronic lymphocytic leukaemia (CLL). But there are some factors that may increase your risk of developing it.
Having one or more risk factors doesn't mean that you will definitely get leukaemia.
Risk factors for CLL include:
Your risk of developing CLL increases as you get older. It is very rare in people younger than 40.
Men are more likely to develop CLL than women. We don't know why that is.
We know that there is some kind of inherited genetic change in some people with CLL. But most people with CLL do not have a family history of it.
You have a higher risk of developing CLL if a close family member (parent, sibling, child) has CLL. But most people with a family history of CLL do not develop it themselves.
Where there isn't clear evidence
Some factors might increase the risk of CLL but there is not enough evidence to be sure.
Exposure to chemicals
Some studies suggest that certain hair dyes might increase the risk of developing CLL. But we need more research to clarify if hair dye use today increases the risk of CLL.
Living on a farm,or being exposed to herbicides and pesticides may be linked to an increased risk of CLL.