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Who Gets Multiple Sclerosis? Epidemiology of MS

While MS is not contagious or directly inherited, epidemiologists have identified factors that may influence who gets the disease. Learn more.

Diagnosed in 1995


In this article

How many people live with multiple sclerosis?

Nearly 1 million people are living with MS in the United States, according to a 2019 study funded by the National MS Society. This is more than twice the previously reported number from a national study in 1975 and subsequent updates.

Epidemiology of MS

According to the CDC, epidemiology is the branch of medicine that studies the distribution (frequency, pattern) and determinants (causes, risk factors) of health-related states and events in specified populations. The scientists who work in this field are called epidemiologists.
While MS is not contagious or directly inherited, epidemiologists have identified factors involved in the distribution of MS around the world. These factors include gender, genetics, age, geography and ethnic background. Understanding what causes MS will help us find more effective ways to treat it and — ultimately — cure it, or even prevent it from occurring in the first place.

Graphic - Society-led study confirms nearly 1 million people living with MS in the U.S., twice as many as the previous estimate. Map of U.S. shows prevalence by region per 100,000 residents: Northeast 377, Midwest 353, South 277, West 277  Graph shows prevalence by gender: 1976 estimate: 37 percent male, 63 percent female. 2017 estimate, 74 percent female, 26 percent male.
 A 2019 study confirmed that nearly 1 million people are living with MS in the U.S., more than twice the previous estimate.


At what age is MS usually diagnosed?  

Most people are diagnosed between the ages of 20 and 50, although MS can occur in young children and older adults.

Where is MS most commonly found? 

In general, MS is more common in areas farthest from the equator. However, prevalence rates may differ significantly among groups living in the same geographic area regardless of distance from the equator.
What are the statistics on gender in MS?

The recent prevalence study shows MS is 3 times more common in women than in men. This suggests that hormones may also play a significant role in determining susceptibility to MS.
Does ethnic background affect who gets MS?

Research has demonstrated that MS occurs in most ethnic groups, including African Americans, Asians and Hispanics/Latinos, but is most common among white people of northern European descent. Susceptibility rates vary among these groups, with recent findings suggesting that African American  women have a higher than previously reported risk of developing MS.

What is the genetic risk of MS? 

MS is not an inherited disease, meaning it is not a disease that is passed down from generation to generation. About 200 genes have been identified that each contribute a small amount to the overall risk of developing MS. In the general population, the risk of developing MS is about 1 in 750-1000. 

What are other risk factors for MS? 

Evidence shows that low vitamin D levels, smoking and obesity all play important roles in the development of MS. Many viruses and bacteria have been or are being investigated in connection with MS as well. A growing number of research findings indicate that previous infection with Epstein-Barr virus (EBV), the virus that causes mononucleosis, contributes to the risk of developing MS.  

Learn more about the possible causes of MS.

Epidemiological estimates

Although more people are being diagnosed with MS today than in the past, the reasons for this are not clear. Likely contributors include greater awareness of the disease, better access to medical care and improved diagnostic capabilities. There is no definitive evidence that the rate of MS is generally on the increase.

Additional resources


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