Relapsing-remitting multiple sclerosis (RRMS) causes recurring episodes of inflammation and nerve damage, whereas primary-progressive multiple sclerosis (PPMS) progresses more gradually.

Multiple sclerosis (MS) is a chronic condition with an uncertain cause.

The most common theory suggests that MS begins as an inflammatory process of the autoimmune system that causes damage to the myelin sheath. This is the protective covering that surrounds the nerves of the central nervous system (CNS).

Another theory suggests a virus, such as Epstein-Barr, could be a trigger of MS.

The four main types of MS are:

  • clinically isolated syndrome (CIS)
  • relapsing-remitting MS (RRMS)
  • primary-progressive MS (PPMS)
  • secondary-progressive MS (SPMS)

Keep reading to find out how PPMS differs from RRMS.

PPMS is one of the rarest types of MS, affecting about 10–15% of everyone receiving an MS diagnosis, according to the National MS Society. While other MS types are characterized by acute attacks, called relapses, followed by periods of non-activity, called remission, PPMS causes gradually worsening symptoms.

PPMS can change over time. A period of living with this condition can be classified as:

  • Active with progression: This means there’s an increase in disabling symptoms, new MRI activity, or a relapse.
  • Active without progression: This means there’s no increase in disabling symptoms, and the symptoms have not become more severe, but MRI activity is present.
  • Not active without progression or MRI activity: This means there’s no increase in disabling symptoms, and no MRI activity is present.
  • Not active with progression: This means there’s no increase in disabling symptoms, but there are relapses or MRI activity.

What are common PPMS symptoms?

PPMS symptoms can vary, but typical symptoms include:

  • vision problems
  • difficulty talking
  • problems walking
  • trouble with balance
  • general pain
  • stiff and weak legs
  • trouble with memory
  • fatigue
  • bladder and bowel issues
  • depression

Who gets PPMS?

People tend to receive a PPMS diagnosis in their 40s and 50s, while those receiving an RRMS diagnosis tend to be in their 20s and 30s.

Females and males are diagnosed with PPMS at the same rates, unlike RRMS, which affects mostly females.

What is the life expectancy for PPMS?

PPMS affects everyone differently. Because PPMS is progressive, symptoms tend to get worse rather than better. Most people have trouble walking. Some people also have tremors and vision problems.

What treatments are available for PPMS?

Treating PPMS is more difficult than RRMS. It includes using immunosuppressive therapies. They may offer temporary help but can only be safely used for a few months to a year at a time.

Ocrelizumab (Ocrevus) is the only FDA-approved medication to treat PPMS.

There’s no cure for PPMS, but treatment can help you manage the condition.

Certain disease-modifying drugs (DMDs) and steroids can help address symptoms. Maintaining a health-promoting lifestyle that includes eating a well-balanced diet and staying physically active, such as exercising, may help. Rehabilitation through physical and occupational therapy may also help.

RRMS is the most common type of MS. It affects around 85% of all people diagnosed with MS, per the National MS Society. Most people are first diagnosed with RRMS. That diagnosis typically changes after several decades to a more progressive course.

The name relapsing-remitting MS explains the course of the condition. It typically involves periods of acute relapses and periods of remission.

During relapses, new symptoms can develop, or the same symptoms can flare up and become more severe. During remission, people can have fewer symptoms, or the symptoms can be less severe for weeks, months, or years.

Some RRMS symptoms can become permanent. These are called residual symptoms.

RRMS is classified as:

  • active when there are relapses or lesions found on an MRI
  • not active when there are no relapses or MRI activity
  • worsening when symptoms get progressively more severe after a relapse
  • not worsening when symptoms do not get progressively more severe after a relapse

What are common RRMS symptoms?

Symptoms vary for each person, but common RRMS symptoms include:

  • problems with coordination and balance
  • numbness
  • fatigue
  • inability to think clearly
  • problems with vision
  • depression
  • problems with urination
  • trouble tolerating heat
  • muscle weakness
  • trouble walking

Who gets RRMS?

Most people are diagnosed with RRMS in their 20s and 30s, which is younger than a typical diagnosis for other MS types, such as PPMS. Females are twice as likely to be diagnosed than males.

What is the life expectancy for RRMS?

This condition affects each person differently. Some people may live a relatively healthy life with only rare relapses that don’t cause significant complications. Others may have frequent attacks with progressive symptoms that eventually lead to severe complications.

In general, however, the overall survival rate in people living with MS is about 7 years shorter than people without the condition. Research indicates that people with RRMS may experience their lifespan reduced by 4 years, while people with RRMS may experience a 10-year lifespan reduction.

What are RRMS treatments?

There are several medications the Food and Drug Administration (FDA) has approved to treat RRMS. These medications tend to reduce the occurrence of relapses and the development of new lesions. They also slow the progression of RRMS.

Although PPMS and RRMS are both types of MS, there are clear differences between them, such as:

Age of onset

A PPMS diagnosis typically occurs in people in their 40s and 50s, while RRMS affects those in their 20s and 30s.


PPMS is progressive, meaning symptoms get worse over time, while RRMS may present acute attacks with long periods of inactivity. RRMS may develop into a progressive type of MS called secondary progressive MS, or SPMS, after a certain period of time.

Treatment options

There are now many FDA-approved medications that can treat different types of MS, and additional ones are being researched.

People living with PPMS and RRMS may also benefit from rehabilitation via physical and occupational therapy.

By definition, PPMS is primary, which means it is the first type of MS that typically develops. When RRMS progresses to a progressive form of MS, it is referred to as secondary or SPMS.

Older research suggested about half of those diagnosed with RRMS would develop SPMS within 10 years, and 90% would develop it within 25 years.

However, with modern treatment options such as disease-modifying drugs, this progression can be significantly delayed.

The most prevalent type of MS is RRMS, which involves recurring episodes of inflammation and demyelination in the central nervous system.

PPMS is characterized by a gradual decline in neurological function without distinct flare-ups or periods of improvement. This form of MS typically causes less inflammation than RRMS, resulting in fewer lesions in the brain and more lesions in the spinal cord.

That said, how MS manifests can vary from person to person. Speak with your doctor to understand your specific outlook, symptoms, and treatment options.