Myeloma causes and risk factors

There are certain things that can increase the chance of developing myeloma. These are called risk factors. Having a risk factor does not mean you will get cancer. And not having risk factors does not mean you will not develop it.

In the UK, around 5,800 people are diagnosed with myeloma each year. Doctors do not know what causes myeloma, but having MGUS (monoclonal gammopathy of unknown significance) increases the risk of developing it. MGUS is a non-cancerous condition where the body makes an abnormal protein, called a paraprotein.

Almost everyone with myeloma has had MGUS first, but it may not be detected. But only a small number of people who have MGUS develop myeloma.

Like other cancers, myeloma is not infectious and cannot be passed on to other people.

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


Myeloma is more common in people over the age of 65. It is very rare in people under the age of 40.


Myeloma is more than twice as common in black people than in white people.


Myeloma is slightly more common in men than in women.

Family history

People who have a close family member (such as a parent, brother or sister) with myeloma may have a very small increase in their risk of developing it. If you are worried about this, your doctor can explain what the risk might be.

Immune system conditions

Some health conditions can weaken the immune system, or cause the immune system to attack healthy cells in the body by mistake (autoimmune disease). These types of conditions may slightly increase the risk of developing myeloma.

Being overweight

Some research suggests that being overweight may increase the risk of developing myeloma. Keeping to a healthy body weight may reduce the risk of myeloma and other cancers.

About our information

  • References

    Below is a sample of the sources used in our myeloma information. If you would like more information about the sources we use, please contact us at

    National Institute for Health and Care Excellence (NICE). Myeloma: diagnosis and management. NICE guideline [NG35]. Published: 10 February 2016 Last updated: 25 October 2018. Available from: Accessed: 19/07/22

    Jonathan Sive et al., on behalf of the British Society of Haematology. British Journal of Haematology. Guidelines on the diagnosis, investigation and initial treatment of myeloma: a British Society for Haematology/UK Myeloma Forum Guideline. Published: 21 March 2021 Available from: Accessed: 19/07/22

    M.A. Dimopoulos et al. Annals of oncology. European Society for Medical Oncology (ESMO). Multiple myeloma: EHA-ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Volume 32, ISSUE 3, P309-322, March 01, 2021. Available from: Accessed: 19/07/22

  • 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, Dr Anne Parker, Consultant Haematologist.

    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.

The language we use

We want everyone affected by cancer to feel our information is written for them.

We try to make sure our information is as clear as possible. We use plain English, avoid jargon, explain any medical words, use illustrations to explain text, and make sure important points are highlighted clearly.

We use gender-inclusive language and talk to our readers as ‘you’ so that everyone feels included. Where clinically necessary we use the terms ‘men’ and ‘women’ or ‘male’ and ‘female’. For example, we do so when talking about parts of the body or mentioning statistics or research about who is affected. Our aims are for our information to be as clear and relevant as possible for everyone.

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