Multiple Sclerosis Facts and Statistics: What You Need to Know

Multiple sclerosis (MS) affects nearly 1 million adults in the United States. MS is considered a generally complex disease. Its symptoms are highly variable and unpredictable, there is no cure, and its cause remains unknown.

To help you gain a "big picture" sense of what MS is, this article will highlight key facts and statistics about multiple sclerosis.

MS Overview

In MS, the immune system attacks the fatty myelin sheath surrounding nerve fibers within the brain and spinal cord. When myelin is damaged or destroyed, the normal transmission of nerve signals is disrupted. This can lead to various symptoms like numbness, weakness, and cognitive problems, among others.

Most people with MS experience a relapsing-remitting MS (RRMS) course, where they experience relapses ("flares") of new or worsening symptoms, followed by periods of symptom improvement or recovery.

Less commonly, people with MS are diagnosed with primary progressive MS (PPMS), where symptoms worsen over time in the absence of discrete relapses.

Even though MS cannot be cured, there are treatments available to help ease symptoms. There are also numerous medications called disease-modifying therapies (DMTs) that can slow the natural progression of the disease.

How Common Is MS?

In 2017, the estimated prevalence of MS in the U.S. was 363 cases per 100,000 people in the population. This is equivalent to nearly 1 million individuals. This number is higher than previous prevalence estimates.

• In 2010, the estimated prevalence was 309 cases per 100,000 people.
• In 1990, the estimated prevalence was around 120 cases per 100,000 people.

It's unclear if the increase in MS cases is because more people are developing the disease or because prior reports underestimated the number of people living with MS. If the rate of MS is increasing, changes in the environment need to be studied to understand why.

MS by Ethnicity

MS is most common among White people of northern European descent. Although, recent research has shown an increasing MS rate among Black people compared to White people. Hispanic and Asian people are still significantly less likely to develop MS than White people.

Specifically, a California study reported Black people to have a 47% increased risk of MS compared to White people. Hispanic Americans and Asian Americans were found to have a 50% and 80%, respectively, lower risk of MS compared with White Americans.

Experts aren't sure why these MS demographics are changing. It's likely that environmental or social factors are involved, as the changes are too fast to be explained by genetic factors.

MS by Age and Gender

MS is generally detected in young adulthood, between the ages of 20 and 40.

That said, the disease can manifest at any age. Less than 1% of cases occur in childhood (pediatric MS), and around 2% to 10% of cases occur after age 50 (called late-onset MS).

In terms of sex differences, MS is three times more common in females than males.

Moreover, females with MS tend to have an earlier onset of disease. Their disability progression is also generally less than males, and females are slightly less likely to have primary progressive MS.

Gender differences in MS may be explained by alterations in sex hormones. This is supported by the fact that MS symptoms change with the natural change of estrogen levels during pregnancy.

Causes of MS and Risk Factors

MS is an autoimmune or "immune-mediated" disease because it involves the immune system launching misguided attacks against healthy tissue (myelin and nerve fibers) in the brain and spinal cord.

While experts believe that MS manifests as a result of a complex interplay between various environmental and genetic factors, the exact cause or "why" behind the disease remains unknown.

Some environmental factors that may play a role in MS development include:

• A deficiency in vitamin D
• Smoking
• Past viral infections (e.g., Epstein-Barr virus)
• Obesity in early childhood
  

What Are the Mortality Rates for MS?

The mortality rate in those with MS compared to the general population is increased.

A 2017 Norwegian study examined people with MS who were diagnosed between the years 1953 and 2012. Investigators found that those living with MS had a seven-year shorter lifespan and a nearly threefold higher risk of death compared to the general population.

Other studies have found a similar increased mortality rate in people with MS, including an increased risk of death from heart disease, lung disease, infection, accidents, and suicide.

All said, MS is rarely fatal. If a person does "die from MS," it usually means their death was related to an MS-related complication, like a urinary tract infection (UTI) or aspiration pneumonia (lung infection caused by inhaled food particles).

Screening and Early Detection

There is no screening test for MS, and the disease cannot necessarily be prevented, considering there are factors (your genes and immune system response) that are out of your control.

Regardless, if you think you may be experiencing possible symptoms of MS, it's important to make an appointment with your healthcare provider or neurologist.

Keep in mind there are some lifestyle habits that experts believe could help stave off the disease in certain individuals or at least help lessen the disease's impact if diagnosed. 

Examples of such habits include:

• Maintaining a normal weight
• Having a sufficient blood vitamin D level
• Avoiding smoking
  

Summary

Nearly 1 million adults in the U.S. are currently living with multiple sclerosis. This lifelong, neurological disease tends to strike in young adulthood and is three times more common in females than males.

The disease can occur in most ethnic groups, although it's more common in White people of northern European descent. Compared to the general population, those living with MS have a nearly threefold higher risk of death.