Prevalence of Multiple Sclerosis

Multiple sclerosis is the most common demyelinating disease and the main cause of neurological disability in young and middle-aged adults in the UK, where it affects about 85,000 people. Age of onset is usually between 20 and 40 years and it is more common in women than in men by about 3.5:1. The symptoms, severity and course of MS vary widely depending partly on the sites of the lesions and also the extent of the demyelination and damage to nerve cell fibres.

The prevalence is greatest in northern European Caucasians and in those of all races born at more northern temperate latitudes or moving north before the age of 15. It is less common in regions closer to the equator. In parts of Northern Europe the prevalence is as high as 1 in 500 individuals while the general prevalence in Europe and North America is about 1 in 800.

Amended April 2008