Active vs. Inactive SPMS: What to Know
Health ConditionsNeurological DisordersMultiple Sclerosis

Active vs. Inactive Secondary-Progressive MS: Understanding the Difference — and Why It Matters

Active vs. Inactive Secondary-Progressive MS: Understanding the Difference — and Why It Matters
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Published on September 16, 2025
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If you have secondary progressive multiple sclerosis (SPMS), your doctor may have described it as “active” or “inactive.” You may be wondering what these terms mean and why they matter.

“If we’re at a point where someone hasn’t had a relapse in a long time, we might call that inactive SPMS,” says Dorlan Kimbrough, MD, a board-certified neurologist at Duke Neurological Disorders Clinic, in Durham, North Carolina. “But as soon as they have an event, then it becomes active SPMS.”

“It may sound simple, but the distinction can actually be hard to make. In reality, there’s not a neat transition,” he adds. But because the type of SPMS you have — active vs. inactive — can affect which treatments you’re given, it’s important to learn as much as you can about the differences.

What Is Active SPMS?

If you have active SPMS, that means you’re experiencing some inflammation, either because you’re having a relapse of symptoms or because an MRI scan is showing signs of inflammation, says Dr. Kimbrough.

He uses a popcorn analogy to describe active SPMS: “When you’re microwaving popcorn, there’s sometimes a lot of popping. And when you get towards the end, you can tell it’s slowing down,” Kimbrough says. “But then you pour the popcorn into your bowl, and suddenly there’s a pop — like one of the last little kernels heated up. That’s what the ‘active’ period is like.”

Some research suggests that, at a given time, about 27 percent of people with SPMS are in the active phase.

Knowing you have active SPMS is important, because it determines the course of treatment. Active SPMS can be treated with medications called disease-modifying therapies, which can reduce the number of relapses you experience and slow down the damage caused by MS. But the medication can’t stop the disease from progressing altogether.

What Is Inactive SPMS?

If you haven’t had any relapses lately — or your MRIs have shown no signs of inflammation — then you likely have inactive SPMS. Research suggests that about 73 percent of people with SPMS have the inactive form,

 which may also be referred to as "non-active" or "non-relapsing" SPMS.

Despite the name, inactive SPMS doesn’t mean the disease isn’t progressing. Because SPMS worsens over time, it’s possible that people with inactive SPMS may experience more trouble functioning in the future, even if they’re no longer having relapses.

Unfortunately, there are few treatment options for inactive SPMS. “Our [traditional disease-modifying] treatments are really good at dealing with inflammation and relapses,” says Kimbrough. “But [with inactive SPMS] … where, essentially, there’s damage that accrues over time, very slowly, that’s a little bit trickier to treat.”

That said, a class of drugs called Bruton’s tyrosine kinase (BTK) inhibitors look promising in clinical trials. One in particular, tolebrutinib, has been shown to help slow the progression of inactive SPMS.

 And more BTK inhibitors are actively being studied as potential treatments for this form of SPMS.
Other treatment approaches for inactive SPMS focus primarily on rehabilitation strategies, such as:

  • Occupational therapy, to help improve your ability to do daily tasks and show you how to use assistive devices
  • Physical therapy, to help improve mobility and walking
  • Speech therapy, to help improve your ability to communicate properly and address issues with eating or swallowing

Whether you’re taking medication or not, “It’s very important to have a robust rehabilitation program,” says Kimbrough. “That way, you can preserve the function you still have and maintain more mobility to do the things you need to do.”

Questions to Ask Your Neurologist at Your Next Visit

If you aren’t sure whether you have active or inactive SPMS, here are a few questions you may want to ask your doctor.

Bring These Questions to Your Next Checkup

  • Do I have active or inactive SPMS?
  • Are there signs of disease activity on my MRI?
  • Can I expect a relapse in the future?
  • What treatment, if any, might be appropriate for me right now?
  • When might I want to change treatments (if at all)?
  • How often should the SPMS be monitored?
  • Are there any rehabilitation strategies you recommend?
  • Are there any other symptom relief strategies I can try?

The Takeaway

  • Secondary progressive multiple sclerosis (SPMS) is a form of MS that gradually worsens functioning and usually comes after relapsing-remitting MS.
  • SPMS can be active or inactive — meaning, with relapses or without relapses, respectively — but damage can still occur with inactive SPMS.
  • Inactive SPMS is traditionally harder to treat than active SPMS, with current treatments focusing primarily on rehabilitation and symptom relief.
EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
  1. Secondary Progressive Multiple Sclerosis (SPMS). Cleveland Clinic. July 30, 2025.
  2. Chisari CG et al. Active and Non-Active Secondary Progressive Multiple Sclerosis Patients Exhibit Similar Disability Progression: Results of an Italian MS Registry (ASPERA). Journal of Neurology. October 2024.
  3. Active MS and MS With Progression. MS Society. June 23, 2022.
  4. Secondary Progressive Multiple Sclerosis (SPMS). National Multiple Sclerosis Society.
  5. Fox RJ et al. Tolebrutinib in Nonrelapsing Secondary Progressive Multiple Sclerosis. The New England Journal of Medicine. May 15/22, 2025.
  6. Rehabilitation. National Multiple Sclerosis Society.
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Jessica Baity, MD

Medical Reviewer
Castle Connolly Top Doctor

Jessica Baity, MD, is a board-certified neurologist practicing in southern Louisiana. She cares for a variety of patients in all fields of neurology, including epilepsy, headache, dementia, movement disorders, multiple sclerosis, and stroke.

She received a bachelor's degree in international studies and history from the University of Miami and a master's in international relations from American University. She graduated from the Louisiana State University School of Medicine, where she also did her internship in internal medicine and her residency in neurology.

Prior to practicing medicine, she worked in international relations and owned a foreign language instruction and translation company. 

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Maria Masters

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Maria Masters is a contributing editor and writer for Everyday Health and What to Expect, and she has held positions at Men's Health and Family Circle. Her work has appeared in Health, on Prevention.com, on MensJournal.com, and in HGTV Magazine, among numerous other print and digital publications.

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