Statistics: Who Gets MS?

Multiple sclerosis (MS) is not contagious. This means it is not spread from person to person. MS also is not heritable, or passed down from parent to child. There is currently no single known cause of MS. But there are doctors who study patterns in diseases, called epidemiologists. These doctors have found several risk factors that seem to contribute to MS incidence (the frequency of disease) in specific groups of people.¹

There are currently around 1 million people in the United States living with MS. Worldwide, a little under 3 million people have MS. The global incidence of MS in 2020 was 35.9 cases per 100,000 people. Understanding who gets MS can help doctors to make important discoveries in finding out what causes it.^1,2

Age and MS incidence

Most people are diagnosed with MS between the ages of 15 and 50. The average age of diagnosis is 32. MS is more commonly diagnosed in young adults. This is because many people have their first MS symptoms in early adulthood. MS can also occur in young children and older adults, but this is more rare.^1,3-4

Geographical differences in MS incidence

MS is more common in people from Europe, the United States, Canada, New Zealand, and parts of Australia. It is less common among people in Asia and Africa. It is also less common in areas of the world closer to the equator. High-altitude regions far from the equator, above or below the 40-degree mark north or south, have higher rates of MS.^1-2,4

There are also differences in MS incidence within the United States. The Northeast and Midwest regions have the highest incidence. By contrast, the South and West having the lowest.¹

Gender and MS incidence

MS, like other autoimmune diseases, is more common in women than men. MS occurs up to 3 times more commonly in people assigned female at birth than those assigned male at birth. In some countries, the likelihood of having MS if you were assigned female at birth increases up to 4 times. This could potentially suggest a hormonal link to MS. But there have not been any scientific studies done to prove this.¹

Race and ethnicity in MS incidence

MS is more common among Caucasians. This is especially true if they live far from the equator. People of Danish descent and those living in the Orkney Islands have some of the highest rates of MS in the world. It is rare among some ethnic groups, including:^1,2,5

• Inuit
• Yakutes
• Hungarian Romani
• Norwegian Lapps
• Australian Aborigines
• Maoris

In the United States, MS incidence is highest to lowest in:^1,2,5

1. Non-Hispanic white populations
2. Non-Hispanic Black populations
3. Other non-Hispanic race and ethnic groups
4. Hispanic populations

Other factors affecting MS incidence

Several other factors influence MS risk in large populations of people. Some studies have linked MS incidence to:^1,4,6

• Certain inherited genes
• Epstein-Barr, the virus that causes mononucleosis
• Environmental factors such as vitamin D, sunshine, and place of birth
• Smoking
• Obesity