Motor Neurone Disease (MND)

Possible causes of MND (including inherited forms of MND)

Most people who develop MND have no family history of the condition, and it is extremely unlikely to develop in other family members. (See below for familial or inherited MND). Little is known about what causes this form of MND. It is thought that MND is caused by a mix of genetic and environmental factors, and several possible factors have been suggested, including exposure to chemicals, fractures and injuries, smoking, military service, and engaging in some sports or high levels of exercise, but research studies have so far failed to find clear conclusive evidence. Probably lots of different factors are involved, and in any one person MND is likely to occur for complex reasons, rather than there being any single cause. Several factors may increase the risk of developing MND or may help to 'trigger' it, but may not be enough in themselves to cause it.

Some people we talked to felt there was little point worrying about what had caused their condition or whether they had done something to cause it. Lots of people asked themselves 'Why me?' but at the same time many felt it was important that people should not blame themselves. Some also pointed out that it would not make any difference to their condition even if they did know what caused it. 

Not knowing what had caused their condition was frustrating for some people. While some could live with the idea that it was just chance, others struggled with this idea, especially if they and their families had always been very fit and healthy. 

Some had done a lot of reading and searching on the internet for different theories about causes and the latest research evidence. 

People mentioned a wide variety of what they thought might be possible risk factors from their own experience, including:

  • A stressful lifestyle or particularly stressful events
  • Diet
  • Exposure to chemicals (especially in agricultural work and on food, but also when working as a firefighter and installing industrial machinery)
  • Exercise, sport and sports injuries
  • Other injury (including head injuries and leg injuries)
  • Previous chemotherapy and surgery
  • Medication for depression
  • Amalgam teeth fillings
  • Throat infections, viruses
  • Lyme disease
  • Genetics
  • Frequent travelling (including muscle cramps caused by sitting still for long periods).

Some people we talked to, who had younger children, worried especially about whether their MND might be an inherited form. Knowing that MND runs in the family raises particular issues for people about whether they themselves will get the condition, and whether their children and other family members will also get the condition. Gene testing is not always possible, if there is no clear family history.

See our resources for links to further information on research around causes of MND. You can also find out more on the Research pages of the MND Association website.

Last reviewed August 2017.
Last updated August 2017.


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