What are risk factors?

Doctors do not know exactly what causes non-Hodgkin lymphoma. But some things may increase your risk of developing it. These are called risk factors.

Having these risk factors does not mean you will get lymphoma. Many people affected by lymphoma do not have any risk factors.

If you are worried about lymphoma and would like to talk to someone, we're here. You can:


NHL can affect people at any age. But it is more common in people who are over 50.


Lymphoma is slightly more common in men than women.


Some viruses or bacteria can increase the risk of developing NHL:

  • Helicobacter pylori infection sometimes causes a type of NHL called MALT lymphoma.
  • Epstein Barr virus (EBV) infection, which causes glandular fever, may slightly increase the risk of developing some types of NHL.
  • Human T-lymphocytotrophic virus-1 (HTLV-1) is a rare infection that is linked with T-cell lymphoma in some people.

Most people who have had these infections will not develop lymphoma.

Lymphoma is not infectious and cannot be passed on to other people.

A weakened immune system

If your immune system is weak, you have a higher risk of developing lymphoma.

Conditions such as HIV can weaken the immune system. We have more information about lymphoma and HIV.

Drugs called immunosuppressants can also weaken the immune system. Some people need these drugs after an organ transplant or to treat auto-immune disease.

Auto-immune disease

Auto-immune diseases develop when the immune system attacks healthy body tissue by mistake. Several auto-immune diseases can increase the risk of lymphoma. These include:

  • coeliac disease
  • Sjogren’s syndrome
  • rheumatoid arthritis
  • systemic lupus erythematosus.

Doctors do not fully understand why these diseases increase the risk of developing lymphoma. It may be because of the diseases themselves, or the treatments used to control them.

A previous cancer

NHL is slightly more common in people who have had cancer before. This may be because of the cancer or because of the cancer treatments. Radiotherapy and some chemotherapy drugs can increase the risk of developing NHL many years later. But the risk is small compared to the benefit of having the treatment.

Having a close relative with non-Hodgkin lymphoma

People who have a parent, brother or sister with lymphoma have a higher risk of developing NHL. The reason for this is not known. It may be because there is a genetic change that runs in families. Or it could be because people within one family tend to have the same lifestyle factors.

This risk is still very small. Most people who have a close relative with lymphoma will not develop lymphoma.

Breast implants

Breast implants are linked with a lymphoma called breast implant-associated anaplastic large cell lymphoma (BIA-ALCL). This is a rare type of lymphoma. The risk of women with breast implants developing it is very small.

About our information

  • References

    Below is a sample of the sources used in our non-Hodgkin lymphoma (NHL) information. If you would like more information about the sources we use, please contact us at  cancerinformationteam@macmillan.org.uk

    National Institute of Health and Care Excellence (NICE). Blood and bone marrow cancers. NICE Pathways. Last accessed 3 December 2020.

    Non-Hodgkin’s lymphoma: diagnosis and management; NICE Guideline (July 2016).

    Newly Diagnosed and Relapsed Follicular Lymphoma: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up; European Society for Medical Oncology (2020).

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer. It has been approved by Senior Medical Editor, Professor Rajnish Gupta, Macmillan Consultant Medical Oncologist.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.

Date reviewed

Reviewed: 01 March 2021
Next review: 01 March 2024

This content is currently being reviewed. New information will be coming soon.

Trusted Information Creator - Patient Information Forum
Trusted Information Creator - Patient Information Forum

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