Multiple sclerosis (MS) is a chronic disease that affects the central nervous system. Nerves are coated in a protective layer called myelin, which speeds up the transmission of nerve signals. People with MS experience progressive deterioration of myelin.

The four main types of MS are:

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

Relapsing-remitting MS is the most common form of the disease. People with RRMS have acute attacks followed by periods of remission in which the disease doesn’t progress. When this form becomes progressive, it’s called secondary progressive MS.

The rarest form, primary progressive MS, is progressive from the start. There are no acute relapses or remissions in PPMS. About 15 percent of people with MS are diagnosed with PPMS.

People with PPMS experience a decline of neurologic function over time. It becomes increasingly difficult for signals from the brain to get through to the rest of the body.

However, the rate of progression can vary. It’s possible for people to maintain a steady state without new or worsening symptoms for extended periods. There are no clear relapses and remissions like those of RRMS.

Common early symptoms of PPMS include weakness in the legs and problems with walking. These symptoms typically get worse over a period of two years.

PPMS affects people differently, but other symptoms typical of the condition include:

  • stiffness in the legs
  • problems with balance
  • memory problems
  • numbness, tingling, or both, in different parts of the body
  • pain
  • weakness
  • tiredness
  • trouble with vision
  • bladder or bowel dysfunction
  • cognitive changes or mood disorders, including depression
  • sexual function issues
  • fatigue
  • depression

Diagnosing any form of MS can take a long time. That’s because no single test can confirm MS. To reach a diagnosis, your doctor may:

  • evaluate your symptoms
  • review your neurological history
  • conduct a physical examination focusing on your muscles and nerves
  • perform visual tests
  • conduct an MRI scan of your brain and spinal cord
  • perform a lumbar puncture to check for signs of MS in the spinal fluid
  • conduct evoked potentials (EP) tests to identify the specific type of MS; EP tests stimulate sensory nerve pathways to determine electrical activity of the brain

It’s important to work with your doctor to pinpoint which of the four types of MS you may have. This is because each type has a different outlook and different courses of treatment.

Doctors often have a harder time diagnosing PPMS in comparison to other types of MS and other progressive conditions. A neurological issue needs to have progressed for one or two years for someone to receive a PPMS diagnosis.

While other types of MS typically get diagnosed when people are in their 20s, PPMS is usually diagnosed when people are in their 30s and 40s. PPMS typically affects men and older women, unlike RRMS, which affects mostly younger women.

Before making the diagnosis, other conditions with similar symptoms must be ruled out. Other diseases that have symptoms similar to PPMS include:

  • a vitamin B-12 deficiency that causes similar symptoms
  • Lyme disease
  • viral infections, such as human T-cell leukemia virus type 1 (HTLV-1)
  • an inherited condition that causes stiff, weak legs
  • forms of arthritis, such as spinal arthritis
  • a tumor near the spinal cord

PPMS progresses once symptoms start, which is why it’s called primary progressive. There may be periods of active progression and then periods of stability without new symptoms.

What differentiates PPMS from the relapsing forms is that while active progression may stop temporarily, the symptoms don’t resolve. In relapsing forms, the symptoms may actually improve or abilities can return near to where they were before the most recent relapse.

Another difference is that there’s not as much inflammation in PPMS compared to relapsing forms. Because of this, many of the drugs that work for relapsing forms don’t work for PPMS or SPMS.

With PPMS, there are also generally fewer lesions in the brain and more in the spinal cord. The progression of symptoms can worsen over a few months or several years.

Ocrelizumab (Ocrevus) is the only drug approved by the Food and Drug Administration (FDA) to treat PPMS. It reduces nerve degeneration.

However, there are many treatments that may help with the progression of PPMS symptoms. These immunosuppressive therapies include:

  • azathioprine (Imuran)
  • cladribine (Mavenclad)
  • cyclophosphamide
  • methotrexate (Trexall)

Some medications are used to treat specific symptoms of PPMS. Targeted therapies may help symptoms such as bladder and bowel dysfunction, erectile dysfunction, and spasticity. Over-the-counter and prescription medications can help relieve aches and pains.

There are a variety of disease-modifying therapies (DMTs) and steroids approved by the FDA for relapsing forms of MS. These medications usually work by decreasing inflammation. Since PPMS does not involve significant inflammation, these drugs are often not recommended.

Ultimately, the treatment plan that your doctor recommends will depend on your symptoms and overall health.

Maintaining healthy lifestyle habits can be helpful for managing PPMS.

For example, people with PPMS may be able to relieve some symptoms with exercise and stretching. This can preserve mobility, control weight gain, and increase energy levels.

Eating a nutritious diet and staying on a regular sleep schedule are also beneficial. Here are some basic lifestyle tips that may improve your overall health and quality of life:

  • Choose a diet rich in nutritious foods, such as vegetables and fruits, whole grains, and lean proteins.
  • Avoid foods that are high in empty calories, such as sugary sodas, candy, or fried foods.
  • Get regular exercise to help strengthen muscles and boost energy.
  • Practice gentle exercise programs like tai chi and yoga to help with balance, flexibility, and coordination.

Some people find that massage, meditation, or acupuncture help to relieve stress and ease pain. Physical and occupational therapy can also teach strategies for increasing mobility and managing symptoms, leading to improved quality of life.

Take advantage of assistive devices that can help you function and maintain your independence. You can also apply for accessibility accommodations and services. For example, if you drive, consider applying for a special parking permit.

The exact cause of MS is unknown, but doctors have suggested two different theories.

One is that MS begins as an inflammatory process of the autoimmune system that causes loss of myelin. The second is that the disease may be an immune response triggered by a viral infection. This can later cause nerve degeneration or damage.

Research into what may trigger the immune system response responsible for MS is ongoing. Possibilities include viruses or environmental toxins. Why some people develop PPMS is also unknown. MS in any form isn’t contagious.

Four modifiers are used to characterize PPMS over time:

  • Active with progression: PPMS with worsening symptoms and relapses or with new MRI activity; increasing disability will also occur
  • Active without progression: PPMS with relapses or MRI activity, but no increasing disability
  • Not active with progression: PPMS with no relapses or MRI activity, but with increasing disability
  • Not active without progression: PPMS with no relapses, MRI activity, or increasing disability

A key characteristic of PPMS is the lack of remissions.

Even if a person with PPMS sees their symptoms stall — meaning that they don’t experience worsening disease activity or an increase in disability — their symptoms don’t actually improve. With this form of MS, people don’t regain functions they may have lost.

If you’re living with PPMS, it’s important to find sources of support. There are options to seek support on an individual basis or in the wider MS community.

Living with a chronic illness can take an emotional toll. If you’re experiencing ongoing feelings of sadness, anger, grief, or other difficult emotions, let your doctor know. They may refer you to a mental health professional who can help.

You can also look for a mental health professional on your own. For example, the American Psychological Association offers a search tool to find psychologists throughout the United States. also offers a treatment referral helpline.

You may find it helpful to talk to other people who are living with MS. Consider looking into support groups, either online or in-person. The National MS Society offers a service to help you find local support groups in your area. They also have a peer-to-peer connection program run by trained volunteers who live with MS.

As with other forms of MS, symptoms vary tremendously from person to person, as does the rate of progression. Over time, people with PPMS may develop problems walking and moving around independently.

Fatigue and other symptoms may make it difficult to perform everyday activities. However, most people with MS have a normal or near-normal lifespan. If you have PPMS, be sure to see your doctor on a regular basis.

There’s no cure for PPMS, but treatment makes a difference. Although the condition is progressive, people can experience periods of time where symptoms don’t actively worsen.

If you’re living with PPMS, your doctor will recommend a treatment plan based on your symptoms and general health. Developing healthy lifestyle habits and staying connected to sources of support can also help you maintain your quality of life and overall well-being.