Some things make it more likely that you'll get a disease. Doctors call these risk factors. Here we've listed the risk factors for non-Hodgkin's lymphoma.[3] [1]

* Getting older. About half the people diagnosed with non-Hodgkin's lymphoma are over 60.[2]
* Having a transplanted organ, such as a new kidney, heart or liver.[3] If you have a transplant, you need to take a powerful drug that prevents your immune system rejecting the new organ. With your immune system weakened by this drug, you're more likely to get lymphoma.
* Having AIDS.[3] See our articles on HIV infection for more.
* Having had chemotherapy and radiotherapy for some types of cancer in the past.[3]
* Getting some infections. Some types of non-Hodgkin's lymphomas can be caused by certain viruses, such as the Epstein-Barr virus. But this is rare in the UK. Here, viruses cause very few non-Hodgkin's lymphomas. To read more, see Infections and lymphomas.
* Having severe coeliac disease that hasn't been treated. People with coeliac disease can't tolerate a substance called gluten, which is found in wheat, rye and barley. If you have coeliac disease, gluten causes damage by making your body's own immune system attack the lining of your bowel. Some people with coeliac disease also react to oats. But people whose disease is treated aren't any more likely to get non-Hodgkin's lymphoma than people who don't have this disease. So if you have coeliac disease, it's important to get it treated.
* Being born with a faulty immune system. Some conditions run in families and make it more likely that you'll get non-Hodgkin's lymphoma.[2] They are ataxia-telangiectasia, common variable immunodeficiency, severe combined immunodeficiency, Wiskott-Aldrich syndrome and X-linked lymphoproliferative syndrome. But these conditions are rare.[1]

References
Armitage J, Mauch PM, Harris NL. Lymphomas. In: DeVita V, Hellman S, Rosenberg S (editors). Cancer: Principles and Practice of Oncology. 6th edition. Lippincott Williams and Wilkins, New York, USA; 2001.

Mounter PJ, Lennard AL. Management of non-Hodgkin's lymphomas. Postgraduate Medical Journal. 1999; 75: 2-6.

Cancer Research UK. Specific cancers, Non-Hodgkin's lymphoma. Available at http://www.cancerresearchuk.org (accessed on 16 January 2008).

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