Non-Hodgkins Lymphomas (cont.)

Risk factors

Doctors seldom know why one person develops non-Hodgkin lymphoma and another does not. But research shows that certain risk factors increase the chance that a person will develop this disease.

In general, the risk factors for non-Hodgkin lymphoma include the following:

  • Weakened immune system: The risk of developing lymphoma may be increased by having a weakened immune system (such as from an inherited condition or certain drugs used after an organ transplant).


  • Certain infections: Having certain types of infections increases the risk of developing lymphoma. However, lymphoma is not contagious. You cannot catch lymphoma from another person.


  • The following are the main types of infection that can increase the risk of lymphoma:

    • Human immunodeficiency virus (HIV): HIV is the virus that causes AIDS. People who have HIV infection are at much greater risk of some types of non-Hodgkin lymphoma.


    • Epstein-Barr virus (EBV): Infection with EBV has been linked to an increased risk of lymphoma. In Africa, EBV infection is linked to Burkitt lymphoma.


    • Helicobacter pylori: H. pylori are bacteria that can cause stomach ulcers. They also increase a person's risk of lymphoma in the stomach lining.


    • Human T-cell leukemia/lymphoma virus type 1 (HTLV-1): Infection with HTLV-1 increases a person's risk of lymphoma and leukemia.


    • Hepatitis C virus: Some studies have found an increased risk of lymphoma in people with hepatitis C virus. More research is needed to understand the role of hepatitis C virus.


  • Age: Although non-Hodgkin lymphoma can occur in young people, the chance of developing this disease goes up with age. Most people with non-Hodgkin lymphoma are older than 60. (For information about this disease in children, call the NCI's Cancer Information Service at 1-800-4-CANCER.)

Researchers are studying obesity and other possible risk factors for non-Hodgkin lymphoma. People who work with herbicides or certain other chemicals may be at increased risk of this disease. Researchers are also looking at a possible link between using hair dyes before 1980 and non-Hodgkin lymphoma.

Having one or more risk factors does not mean that a person will develop non-Hodgkin lymphoma. Most people who have risk factors never develop cancer.