The average life expectancy for someone with multiple sclerosis is about 5 to 10 years shorter than the general population. For a person diagnosed today without severe disabilities, that translates to a median survival of roughly 30 to 35 years after diagnosis. These numbers have been improving steadily thanks to modern treatments, and many people with MS live into their 70s and beyond.
How MS Shortens Life Expectancy
MS itself is the leading cause of death in people who have the disease, listed as the primary cause on death certificates in over 56% of cases in a 60-year population study published in the Journal of Neurology, Neurosurgery & Psychiatry. This doesn’t mean the disease kills suddenly. Instead, severe disability over time leads to complications like respiratory infections, difficulty swallowing, pressure injuries, and reduced mobility, all of which compound over years and eventually become life-threatening.
Cardiovascular disease is the other major concern. People with MS share many overlapping risk factors for heart disease, and a 25-year analysis of U.S. mortality data found that MS-related cardiovascular deaths surged between 1999 and 2023, accounting for over 53,000 deaths in that period. The connection likely stems from reduced physical activity as disability increases, combined with side effects of long-term medication use and the chronic inflammation that MS itself drives.
Disability Level Matters More Than Diagnosis Date
The single biggest predictor of how long someone with MS will live is how much physical function they retain. Researchers have mapped life expectancy to the Expanded Disability Status Scale (EDSS), which doctors use to track how MS affects walking, coordination, and independence. The numbers paint a clear picture of why slowing disability progression is so important.
A newly diagnosed person without severe disabilities can expect around 30 to 35 years of remaining life. When someone loses the ability to walk independently (typically around age 51 on average), their life expectancy is about 13.3 additional years. At the most severe disability levels, where a person is essentially bedbound, life expectancy drops to roughly 1.1 additional years. These milestones aren’t inevitable. Many people never reach severe disability, especially with early and consistent treatment.
How Modern Treatments Are Changing the Numbers
Disease-modifying therapies have made a measurable difference. A large Canadian study following nearly 6,000 people with relapsing MS found that those who took beta interferons (one of the earliest classes of MS medications) for more than six months had a 32% lower risk of death compared to those who never used them. People who stayed on treatment for more than three years saw even greater benefits.
That study looked at older medications. The newer, more potent therapies available today are significantly more effective at preventing relapses and slowing disability progression, which suggests the life expectancy gap will continue to narrow. The key takeaway is that staying on treatment matters, and starting early matters even more, because the real threat to longevity isn’t MS in the abstract but the accumulated disability it causes over decades.
Lifestyle Factors That Affect Progression
Smoking is one of the clearest modifiable risks. Daily smokers with MS see significantly faster disability progression. In one study, daily smokers had more than double the risk of worsening disability compared to nonsmokers. Even former smokers carried elevated risk, with a 3.5 times higher likelihood of progression, though this may partly reflect the damage already done during years of smoking before quitting.
Being overweight also accelerates disability. Overweight patients in the same study progressed faster than those at a normal weight. Interestingly, both the smoking and weight effects were strongest in men with MS, though the reasons aren’t fully understood. Cardiovascular fitness likely plays a role: maintaining heart health through exercise and weight management may protect against both the direct effects of MS and the cardiovascular complications that increasingly threaten people with the disease as they age.
What These Numbers Actually Mean for You
Population averages can feel alarming, but they include people diagnosed decades ago when no effective treatments existed. Someone diagnosed today, who starts treatment early and maintains it, faces a very different outlook than the historical statistics suggest. The 5 to 10 year gap in life expectancy is an average across all types and severities of MS, all treatment histories, and all time periods. Many people with well-managed relapsing MS live close to a normal lifespan.
The factors most within your control are treatment adherence, not smoking, staying physically active, and managing cardiovascular risk factors like blood pressure and cholesterol. These won’t change your MS diagnosis, but they directly influence the trajectory of disability, which is what ultimately determines how MS affects both the length and quality of your life.