Exactly why someone develops multiple sclerosis (MS) isn't known. It's not caused by anything you have done and it's not clear whether it can be prevented.
Multiple sclerosis is a lifelong condition that affects the brain and nerves.
There are many possible symptoms of multiple sclerosis. Common symptoms include tiredness, vision problems and problems with walking or balance.
Multiple sclerosis is caused by your immune system mistakenly attacking the brain and nerves. It's not clear why this happens.
Multiple sclerosis cannot be cured, but medicines and other treatments can help ease some of the symptoms.
Page last reviewed: 20/12/2018
Next review due: 20/12/2021