A risk factor is any factor that is associated with increasing someone’s chances of developing a certain condition, such as cancer. Some risk factors are modifiable, such as lifestyle or environmental risk factors. Others cannot be modified, such as inherited factors or whether someone in the family has had cancer. 

Having one or more risk factors does not mean that you will develop cancer. Many people have at least one risk factor but will never develop cancer, while others with cancer may have had no known risk factors. Even if a person with cancer has a risk factor, it is usually hard to know how much that risk factor contributed to the development of their disease. 

Lymphoma risk factors

There are a range of factors that are associated with the risk of developing lymphoma. There are different risk factors for the different types of lymphoma. 

Non-Hodgkin lymphoma risk factors include: 

• increasing age – most cases occur in people over 60 years old 
• having an immediate relative who has had non-Hodgkin lymphoma slightly increases the risk of developing the cancer^[7] 
• gender – overall, non-Hodgkin lymphoma is slightly more common in men than in women, but certain sub-types of non-Hodgkin lymphoma are more common in women 
• exposure to radiation 
• a weakened immune system, which can occur as a result of autoimmune disease (such as rheumatoid arthritis^[8], coeliac disease^[9] and systemic lupus erythematosus), certain medicines (such as medicines that supress the immune system after an organ transplant) or genetic syndromes 
• chronic infections that cause the immune system to be constantly activated, such as HIV, hepatitis C^[10], Epstein–Barr virus, human T-cell leukaemia/lymphoma virus (HTLV-1), human herpesvirus 8 and infections with Helicobacter pylori^[11] (a type of bacteria) 
• a diet high in meat and fat. 

Other risk factors are possible but have not been confirmed, such as exposure to certain solvents, herbicides and pesticides, and some chemotherapy medicines. 

Hodgkin lymphoma risk factors include: 

• age – Hodgkin lymphoma is more common in early adulthood (especially in people in their 20s) and later adulthood (after 55 years) 
• gender – Hodgkin lymphoma is slightly more common in men than in women 
• a weakened immune system, which can occur as a result of autoimmune disease or certain medicines (such as medicines that supress the immune system after an organ transplant) 
• infection with certain viruses such as Epstein–Barr virus and HIV^[12] 
• having an immediate relative who has had Hodgkin lymphoma slightly increases the risk of developing the cancer 

If you have any of these risk factors or are concerned about your risk for lymphoma, please see your doctor. 

Healthy lifestyle and risk reduction

• Lifestyle and risk reduction 
• Position Statement on Lifestyle risk factors and the primary prevention of cancer