In MS, the brain and spinal cord are mistakenly attacked by our own immune system. This involves autoimmune processes that specifically damage the myelin which forms an insulating layer around nerve fibres. Myelin allows the electrical signals to travel rapidly along the nerves, damage to this myelin leads to a delay or block in the flow of electrical signals. This leads to the symptoms of MS that can include numbness, weakness, visual loss and mobility problems.
Exactly what triggers this autoimmune process in each individual is unclear. However, we do have very good evidence on some of the factors that can contribute to the development of MS across the population as a whole.
These are a combination of genetic and environmental risk factors. Risk factors are features about a person’s biology and life that can contribute to the chances of developing a disease. Each of these factors alone does not mean a person will definitely get MS, but collectively they can increase the likelihood that someone will get MS – and the exact combination of risk factors is likely to be different in each individual.
Understanding the risk factors for MS also helps us to understand the biology of the disease and how we might better treat it, as well as prevent it.