Benign MS is when you’ve had the condition for several years without developing a severe disability. It can take up to 15 years to know if your course is benign. Even so, benign MS can still progress to a more severe form.

Multiple sclerosis (MS) is a chronic condition in which the immune system attacks a fatty substance called myelin that surrounds nerve fibers in the central nervous system (CNS). The immune attack causes inflammation, damaging nerve cells.

Over time, lesions (scar tissue) form, interfering with the CNS’s ability to communicate with other parts of the body. The location of the lesions determines the symptoms, but MS also varies a great deal from person to person.

Benign MS is a form of the condition in which a person has MS for several years without developing any severe disability.

All forms of MS are unpredictable, with varying severity of symptoms. Progression of symptom onset varies also. Common symptoms of MS include:

  • visual disturbances
  • numbness
  • issues with coordination and balance

Some people start out with mild symptoms that take decades to progress, while others experience a rapid progression of symptoms from the beginning. Most people experience something in between.

People who have benign MS have the mildest form of the disease. They may experience symptoms, but their disabilities may not accumulate and an MRI may not show an increase in disease activity. However, symptoms can worsen over time.

The term “benign MS” can be confusing. A person can’t be diagnosed with benign MS from onset, even if initial symptoms are mild. There’s no way to predict if or how MS will progress in the years to come.

According to Johns Hopkins Medicine, about 5 to 10 percent of people with MS have a benign form. Unfortunately, it takes as long as 15 years after an initial diagnosis to know if this type of MS is benign.

Neurologists use the Expanded Disability Status Scale (EDSS) to assess physical impairment. According to the scale, MS is considered benign if there is:

  • no evidence of worsening body functions
  • no increase in disease activity

Relapsing forms

Like benign MS, relapsing remitting MS (RRMS) can change its course. When RRMS transitions into progressive MS, it’s called secondary progressive MS (SPMS). There are no clear attacks or periods of remission in SPMS.

Progressive forms

People with primary progressive MS (PPMS) experience steady worsening of symptoms from onset. There are no clear attacks, and disability accumulates over time.

There is no cure for any form of MS. Treatment involves symptom management and disease-modifying medications.

According to the National Institute of Neurological Disorders and Stroke (NINDS), long-term follow-up of people with benign MS who didn’t take MS medications showed that some eventually became disabled.

People newly diagnosed with MS and those diagnosed with benign MS should discuss the pros and cons of disease-modifying drugs with their neurologists.

Although diagnosis and outlook for benign MS are unclear, there are a few things to keep in mind:

  • Mild symptoms at the time of diagnosis don’t necessarily indicate a benign course of the disease.
  • Benign MS can’t be identified at the time of initial diagnosis; it can take as long as 15 years to diagnose.
  • The course of MS is unpredictable, and having benign MS doesn’t mean that it can’t progress into a more severe form of MS.

MS is a manageable disease. If you’re diagnosed with any form of it, you should weigh the pros and cons of different treatments, including disease-modifying medications, with your doctor.