Multiple Sclerosis (MS) vs. Rheumatoid Arthritis (RA)

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Multiple sclerosis (MS) and rheumatoid arthritis (RA) are both autoimmune diseases that develop in similar ways. An autoimmune disease occurs when the immune system mistakes healthy cells for foreign pathogens and attacks them. While MS and RA can appear similar, the two have distinct differences.

MS targets the brain and spinal cord, attacking the myelin sheath, which is the protective coating found on nerves. RA mainly targets the cartilage in the joints. In some cases, the two diseases can occur simultaneously, which causes confusion in diagnosis and treatment.

This article discusses the similarities and differences between MS and RA, as well as the diagnostic tools used to determine whether a person has MS, RA, or both.

Doctor examining patient in wheelchair

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Both MS and RA have similar disease progression and are often considered the most disabling autoimmune diseases. Similarities between the two diseases include:

  • Consequences: In both RA and MS, the process of damage is caused by chronic inflammation that develops because of an overactive immune system.
  • Tissue damage: The damage done to the tissues in both RA and MS causes a person to experience motor dysfunction in muscles, affecting walking and running.
  • Symptoms: Some symptoms of MS and RA are similar, such as fatigue and weakness. Over time, both diseases also cause problems with mobility in different ways.
  • Treatment: The treatments developed for both diseases are similar and often include medications to reduce inflammation and to suppress the immune system so that it can't cause further damage.
  • Genetic background: Many people with either RA or MS share genetic factors that may be linked to the development of the diseases.
  • Autoantibodies: Antibodies are types of proteins that are designed to help the immune system find and destroy pathogens. Autoantibodies are similar, in the sense that they target and kill cells. However, they are produced by the immune system and then target the body’s own healthy proteins or cells.
  • Progression: Both RA and MS are progressive diseases, meaning they get worse over time. However, with the treatments available, progression usually only occurs if untreated or undertreated.

Because of the similarities between the two diseases, they are sometimes referred to as “siblings.”

When to Consult a Healthcare Provider

If you experience early signs of MS or RA, see a healthcare provider. MS symptoms, such as weakness, fatigue, tingling, and numbness, and early signs of RA, such as fatigue, swelling, pain, stiffness, and tenderness in the joints, should be evaluated by your provider.


The main difference between MS and RA is the area of the body affected by each. In RA, the joints are affected. In MS, there is damage to the central nervous system, which consists of the brain and spinal cord.

The symptoms that occur in both can also differ, although some are the same. The differing symptoms of RA and MS include:

Multiple Sclerosis
  • Vision problems

  • Numbness and tingling

  • Muscle spasms

  • Stiff or weak muscles

  • Cognitive issues that affect thinking, learning, and planning

  • Sexual issues

  • Bladder and bowel dysfunction

  • Tight squeezing feeling around the torso, which is known as an MS hug

Rheumatoid Arthritis
  • Pain in the joints

  • Joint stiffness

  • Joint swelling

  • Tenderness in the joints

  • Joints on both sides of the body are affected at the same time

  • Fever

  • Weight loss

  • Irreversible joint damage

  • Fatigue


Diagnosing MS and RA can be a complicated process, because healthcare professionals have not yet developed one specific test for either condition. Typically, diagnosis can only be done by gathering information from various types of lab tests, as well as physical findings and self-reported symptoms.

The main goal after diagnosing either condition is to investigate:

  • How much damage has been done to the affected areas
  • The progression of the disease
  • How it is continually affecting the body
  • If remission is possible

Remission is a period when the symptoms of disease go away completely or are reduced.

Why Is Early Diagnosis Important?

Since both conditions worsen over time, an early diagnosis is important because it leads to early treatment. The faster treatment begins, the better chance people have at slowing the progression of the disease.


Both MS and RA are autoimmune diseases. The immune system mistakes healthy parts of the body for foreign invaders and begins to destroy them. There are several similarities between the two diseases, such as some symptoms, the type of problems that develop, and how it progresses over time.

However, there are also some differences, including the typical symptoms and the body areas affected. The best way to tell the difference between the two diseases is to judge your symptoms. RA will be most present in the joints, whereas MS can cause symptoms in many areas of the body.

Healthcare providers have to use symptoms, physical attributes of the diseases, and the results from various lab tests to diagnose either condition. An early diagnosis can help reduce disease progression and limit a person's risk of suffering from debilitating symptoms later on.

A Word From Verywell 

Having an autoimmune disease such as MS or RA can be difficult to cope with, because they get worse over time. Remember that both diseases are treatable, and slowing the progression is possible. If you have symptoms of either disease or both, see your healthcare provider for a prompt investigation. MS and RA are similar, but not the same, and it's essential to know what you have for the best possible treatment.

Frequently Asked Questions

  • Is rheumatoid arthritis a symptom of MS?

    Rheumatoid arthritis isn’t a symptom of MS. However, research has shown that there is an increase in rheumatoid arthritis cases in people who already have MS. This doesn’t mean that everyone with MS will develop RA, but they are at an increased risk.

  • What are the key differences between RA and MS?

    The key differences between RA and MS are the dominant symptoms and the parts of the body attacked by the immune system. In MS, the immune system attacks the central nervous system, whereas in RA, it attacks cartilage in the joints.

  • What are the early symptoms of RA?

    There are many early warning signs of RA. Some of these include swelling, stiffness, pain, and aches in the joints. Weight loss and fever can also occur in the early stages of RA. Other early symptoms include fatigue and weakness, symptoms that are also common in MS.

  • What are the early symptoms of MS?

    Since MS affects the central nervous system, early symptoms can develop in various areas of the body. While not everyone with MS will experience all the early signs, they will experience some of them. The early symptoms of MS can include bladder and bowel dysfunction, numbness and tingling in the body, a tight-squeezing feeling around the torso (an MS hug), and weakness and fatigue.

6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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