What is Multiple Sclerosis

Jun 09. 2014

More than 2,000,000 people worldwide have multiple sclerosis. The disease affects almost twice as many women as men. 

Multiple sclerosis (MS) is a disease of the central nervous system: the brain and the spinal cord. It is an autoimmune disease, where the immune system gets confused and instead of attacking an infection or virus it turns on itself and attacks nerve cells.

Cells in the central nervous system are covered in a myelin sheath, a protective layer of fatty protein. It’s a bit like insulation on an electrical cable. The faulty immune system attacks these cells and the resulting damage is called demyelination. Messages from the brain are disrupted, causing them to slow down, become distorted or blocked.

‘Sclerosis’ means scarring. Demyelination causes scars, also known as lesions or plaques, at sites within the central nervous system and the site of these lesions affects the symptoms of the disease and their severity. This is why people with MS experience different symptoms at different times. It is said that no two people experience MS in the same way.

There is no cure for MS, but specialists and treatments can help manage the condition and its effects.

In the earlier stages of MS, the central nervous system can sometimes repair the damaged myelin or use different pathways to get signals through to the rest of the body. This is why episodes of symptoms (relapses) can be followed by periods when symptoms improve or disappear altogether (remission).

Sometimes the actual nerve fibres can be damaged, in addition to the loss of myelin, and it is this nerve damage that causes the increase in disability that can occur over time.

Diagnosis is usually made in people between the ages of 20 and 40, although symptoms may appear earlier and it is possible for both children and older adults to develop MS..


The Multiple Sclerosis International Federation (MSIF) is the world’s only global network of MS organisations. We have 44 member organisations from around the globe, as well links to many other smaller organisations. Together we lead the fight against MS and work to improve the quality of life of people affected by MS wherever they live. 

We bring together the work of MS organisations to help people affected by MS around the world. Along with our members, we campaign for increased international awareness of MS, provide information and support to people affected by MS, and support international research to discover better treatments and ways to manage the disease.