The exact causes of lymphoma are not known. Several factors have been linked to developing lymphoma, but it is unclear what role they play in the actual development of lymphoma.

These risk factors include the following:

Age

Generally the risk of Non-Hodgkin Lymphoma increases with age. Hodgkin’s Lymphoma in the elderly is also associated with poorer prognosis than in younger patients.

Infections

• Infection with HIV
• Infection with human T-lymphocytic virus type 1 (HTLV-1)
• Infection with Epstein-Barr virus (EBV), one of the etiologic factors in mononucleosis
• Infection with Helicobacter pylori, a bacterium that lives in the digestive tract
• Infection with hepatitis B or hepatitis C virus

Medical conditions that compromise the immune system

• HIV (individuals with with AIDS are 50 to 100 times more likely to develop lymphoma than people who are not infected)
• Autoimmune diseases (such as lupus or rheumatoid arthritis)
• Diseases requiring immune suppressive therapy–often following an organ transplant
• Inherited immunodeficiency diseases (severe combined immunodeficiency, ataxia telangiectasia, among others)
• Exposure to toxic chemicals
• Having stomach ulcers or gastritis caused by a kind of bacteria called H. pyelori
• Farm work or an occupation with exposure to certain toxic chemicals such as pesticides, herbicides, or benzene and/or other solvents
• Hair dye, which for more than 20 years has been linked to higher rates of Non-Hodgkin Lymphoma