Multiple Sclerosis (MS): Prevalence and Incidence

The number of people living with multiple sclerosis (MS) grows each year, but the total number of cases is only an estimate because there is no registry available to track new cases. Certain groups—including women, adults under 50, White people of European ancestry, and those who live farthest from the equator—have the highest rates of diagnosis.

Read on to learn more about MS prevalence worldwide and the current state of MS research.

Prevalence

The prevalence of a disease like MS is a measure of how many people in the general population have it. Prevalence can be expressed in a percentage or number. While prevalence statistics are only estimates and based on available data, they can paint a picture of how many people are affected by a disease at any given time.

Prevalence numbers can provide medical professionals with insight into the needs of people with MS, as well as the economic burden of the disease.

An estimated 2.8 million around the world have MS—and that number grew from 2.3 million in 2013. The majority of the 2.8 million people that are diagnosed with MS are adults, however, roughly 30,000 people living with MS are under the age of 18.

Diagnosis Rates

Worldwide data suggest that every region in the world has seen an increase in people being diagnosed with MS since 2013. However, there are still gaps in former estimates about how many people have the disease.

For example, certain methods are used to come up with an estimated number of cases. A 2020 report found that when using the typical method from 2013 to estimate the numbers today, the estimates were off by roughly 30%. When looking at the rates of diagnosis per year, that same report saw that roughly 2.1 people out of every 100,000 people are diagnosed with MS each year.  

Diagnosis rates vary based on region, sex, age, and ethnicity. Women make up the majority of MS cases in the world and are twice as likely to have MS as men. In some areas of the world, there are four cases of MS in women to every one case in men.

The onset of MS typically occurs between the ages of 20 and 50, and the average age at which someone is diagnosed is 32.

Multiple Sclerosis Statistics

Global MS prevalence statistics that include ethnicity and region can show where MS is most documented, as well as who is the most affected by the disease.

By Region

Although MS has increased in every region of the world, some areas are more affected by the disease than others. Research has shown that people who live farther from the equator are more likely to be diagnosed MS than people who live closer to it. This factor may also play a role in why certain ethnic groups are more affected by MS than others.

North America is home to the most people with MS, followed by Europe. The regions of the world that are least affected by the disease are Australasia (Australia, New Zealand, and neighboring islands), Africa, and Oceania (areas of the central Pacific Ocean, such as Micronesia and Polynesia).

By Ethnicity

A person of any ethnicity can develop MS, but some groups are more likely to be diagnosed with it than others. According to the National Multiple Sclerosis Society, white people of European descent are the most likely to be diagnosed with MS. However, more recent data has shown that Black women have a higher risk of developing MS than researchers originally thought.  

The Multiple Sclerosis Association of America looked at data to determine which ethnic groups are most or least affected by MS. People of northern European, including those of Scandinavian descent, are the most likely to develop MS.

Caucasians are more likely to develop MS than people of other races/ethnicities.

In the United States, white Americans are affected by MS more often than people of other racial/ethnic groups. However, MS also occurs in Black, Hispanic, and Asian Americans.

In fact, the numbers of Black and Hispanic Americans being diagnosed with MS are increasing in the United States, which shows that the long-held notion that Black Americans are a low-risk population for MS is not necessarily true.   

Other Facts About MS

When looking at the worldwide prevalence of MS, income appears to be another contributing factor. According to the Atlas of MS, people with higher incomes are more likely to be diagnosed with MS than people with lower incomes.

A person’s socioeconomic status has also been linked to MS disease progression. One study found that people with MS who live in neighborhoods of lower income levels are more likely to reach disability than people living in higher-income areas.

Although the study did not look at why having a lower income may increase the chances of disability for people with MS, the authors suggested that diet and exercise, among other lifestyle factors, may contribute.

Economic Burden of MS

Rates of MS continuing to climb, and people with the disease are forced to utilize health care more often than people who do not have a chronic health condition. As the disease progresses, so does a person's need for health care.

Research has found that although people with MS use more healthcare resources than people who do not have MS, many of them have insurance. Roughly 53.9% of people with MS have private health insurance, 39% have federally funded health care such as Medicare or Medicaid. That leaves 7.7% of people with the disease being uninsured.

However, the costs associated with MS treatment can be high even with insurance, as some specialty drugs can cost more than $600 per month. Annually, the out-of-pocket costs for people with MS can range from $5,900 to $6,400 a year.

With all the variables that go into insurance plans—such as what is covered and the amount of coverage available—the proper treatment and management of symptoms and disease progression in people with MS might be out of reach for many people with the condition.

Ongoing Research

The main goal of studying MS is to figure out what causes it and find new and better ways to treat it. Ongoing research will help more people access treatment that could reduce their symptoms and help prevent disability.

Specific areas of ongoing MS research include the following:

• Biomarkers to help diagnose MS and monitor disease progression
• Genetic and environmental risk factors that contribute to the development of the disease 
• How diet and the collection of bacteria in the gut (microbiome) affect MS
• The mechanisms that cause sex-linked disparities in MS onset and progression
• How the immune system contributes to MS and its symptoms in relation to the central nervous system
• The risk factors and progression of the disease in ethnic populations that were formerly considered low risk
• The basic function of myelin in the body and ways to overcome the loss of myelin that occurs in MS

Summary

MS is considered the most widespread disabling disease in young adults and its prevalence is rising around the world. In fact, some populations that were previously considered to be at low risk for developing MS have also seen rising case numbers in recent decades.

A Word From Verywell

The goal of researchers is to develop a cure for MS, but it's not here yet. Studies are focused on areas that could help treat the disease more effectively and to gain an understanding of why it develops in the first place.

Even without a cure on the horizon, with new treatment options being developed, the millions of people living with MS can cope more effectively with the symptoms of the disease.