Multiple Sclerosis vs. Rheumatoid Arthritis: What Are the Differences?

Multiple sclerosis (MS) and rheumatoid arthritis (RA) are autoimmune diseases, conditions in which the immune system malfunctions and attacks healthy tissues. In MS, those attacks are directed at the myelin sheath that protects nerve cells. In RA, immune system attacks target the synovium—the lining of the joints.  

In MS, attacks on the myelin sheath cause damage that disrupts brain and spinal cord connections and leads to a wide range of symptoms. On the other hand, RA is characterized by joint pain, swelling, and stiffness. RA can also affect the body’s organs, including the skin, eyes, heart, and lungs.  

This article will cover the symptoms, diagnosis, and treatment of MS and RA and the differences between the two conditions.

Symptoms

MS and RA share some symptoms, including numbing and tingling, muscle weakness, chronic fatigue, and problems with mobility, and eye inflammation, which can lead to eye pain and vision problems.  

Multiple Sclerosis 

MS causes many different symptoms that vary from person to person. Some people with MS will experience mild symptoms for most of their lives, while others will have severe symptoms and ongoing disease progression.

Symptoms of MS that usually differ from those of RA include:

• Muscle spasms
  
• Unusual eye movements
• Dizziness and vertigo (spinning sensation)
• Loss of coordination, an unsteady gait (manner of walking and moving), loss of balance, and frequent falls
• Memory problems or problems thinking clearly
• Tremors
• Slurred speech
• Mood swings
• Sexual, bowel, and bladder function problems
• Seizures: According to the Epilepsy Foundation, 60% of people with MS experience focal seizures—seizures that begin in one area of the brain that can become generalized, spreading to other parts of the brain. About 30%–40% of seizures are symptomatic in people with MS. Seizures related to MS flares (times when symptoms worsen) will stop when the flare-up improves, and treatment is generally unnecessary.

Rheumatoid Arthritis

RA causes inflammation and swelling in the linings of the joints. Over time, ongoing inflammation can lead to bone erosion and joint deformity.

Symptoms of RA that usually differ from MS are:  

• Joint pain and stiffness, especially in the small joints of the fingers or toes
• Symmetrical joint involvement, such as both hands, both knees, or both elbows
• Morning joint stiffness upon awakening, or stiffness of joints after long periods of inactivity
• Muscle pain
• Low-grade fevers
• Malaise
• Finger joint deformities

RA is also known for disease complications commonly seen in people with severe RA. Without early and adequate treatment, chronic inflammation can lead to disease consequences.

Complications of RA include:

• Bone loss and decreased bone density
• Skin problems, including painless lumps under the skin, called rheumatoid nodules
• Pericarditis, which is inflammation of the tissue that surrounds the heart leading to chest pain and breathing troubles
• Vasculitis: Inflammation of the blood vessels
• Lung disease: Symptoms include a dry cough and shortness of breath

Causes

The causes of MS and RA are unknown. Researchers believe that both conditions are related to genetics. Having specific genes or a family history can increase your risk for RA or MS.  

Multiple Sclerosis  

MS is believed to be caused by genetics in combination with other factors. Additional factors that might lead to MS are:  

• Infections, mainly from the Epstein-Barr virus
• Vitamin D deficiency
• Obesity
• Smoking
• Chronic stress
• Physical trauma

Rheumatoid Arthritis 

Genes alone are not enough to cause RA. For most people, additional risk factors are necessary for the disease to develop.

Additional risk factors linked to RA are:

• Sex: Around two-thirds of people with RA are female, and research studies point to sex-related factors that increase RA risk, including fluctuating hormones in pregnancy, childhood, and menopause.
  
• Age: RA commonly affects people in middle age, but anyone can get RA, including children and older adults.
• Smoking: Smoking cigarettes increases the risk for RA, especially in people who have a genetic disposition for the disease.
• Family history: If you have a family member with RA, your risk for RA is much higher than people without a family history.
• Being overweight
• Chronic emotional or physical stress
• Infections or severe illnesses

Diagnosis

MS and RA are diagnosed differently. Each has its specific diagnostic criteria and testing methods.  

Multiple Sclerosis

There is no one specific test to confirm MS. A diagnosis of MS typically involves ruling out other conditions that might produce similar symptoms.  

Your healthcare provider will start with a medical history and neurological examination. Let your healthcare provider know about the symptoms you have experienced and any patterns linked to symptoms.

With the neurological exam, your healthcare provider looks for changes to your vision, eye movement, hand and leg strength, balance issues, speech problems, and reflex abnormalities. 

If MS is suspected, additional testing is used to help confirm the diagnosis. This testing might include:  

• Blood tests to rule out other conditions that might cause similar symptoms
• Magnetic resonance imaging (MRI) to look for MS lesions on the brain and spinal cord
• A spinal tap (lumbar puncture), in which a sample of cerebrospinal fluid is removed from the spinal canal and sent to a lab for analysis to look for antibodies associated with MS
• Evoked potential tests to record electrical signals from the nervous system in response to stimuli 

Rheumatoid Arthritis

An RA diagnosis involves a physical examination, medical history, blood work, and imaging.  

Your healthcare provider will want to know about your family history of RA or other autoimmune diseases. They will also ask about the symptoms you are currently experiencing and your medical history.   

Your healthcare provider will check your joints for inflammation (swelling), tenderness, redness, or warmth during the physical exam. They may also check your muscle strength and reflexes.  

Blood tests can help diagnose RA, and might include:  

• Erythrocyte sedimentation rate (ESR or sed rate)
• C-reactive protein level (CRP)
• Complete blood count (CBC)
• Rheumatoid factor (RF) 
• Antinuclear antibody (ANA)
• Anti-cyclic citrullinated peptide (anti-CCP)
  

Imaging studies also are used to diagnose RA. These include:

• X-rays
• MRI
• Ultrasound 

Your healthcare provider might be unable to make a diagnosis based on your physical exam, blood work, and imaging. In that case, they may suggest joint aspiration (using a needle to remove fluid from the space around the joint) and analysis of the synovial fluid to narrow down a diagnosis.

Treatment

There is some overlap in medicines used for MS and RA. Medicines used in treating both conditions are disease-modifying antirheumatic drugs (DMARDs), biologic drug therapies, and corticosteroids. 

Multiple Sclerosis

There is no cure for MS, but many medicines and other treatments can help to control the disease and treat symptoms.  

Treatment for MS will depend on the type of MS and the severity of symptoms. In general, MS can be treated with the following medicines:  

• Corticosteroids to reduce inflammation during MS flares
• DMARDs to reduce flares and slow down progressive MS
• Biologics to target molecules involved in immunopathological processes of MS (immune system processes that cause damage)
• Medicines to manage vertigo
• Central nervous system stimulants to manage fatigue
• Bladder and bowel medicines to treat bladder and bowel dysfunction
• Antidepressants and anti-seizure medications for nerve pain
• Anti-seizure treatments to control frequent seizures and tremors
• Muscle relaxants, benzodiazepines, and Botox (onabotulinumtoxinA) to treat muscle spasms
• Erectile dysfunction medicines for sexual problems
  

Rheumatoid Arthritis  

The main treatment goals in RA are to control inflammation, manage pain, and reduce the potential for joint damage and disability. Treatment for RA includes medicines, physical therapy, occupational therapy, and in some cases, surgery.

Medicines used to treat RA include:

• Nonsteroidal anti-inflammatory drugs (NSAIDs), such as Advil or Motrin (ibuprofen) and Aleve (naproxen) to reduce pain and inflammation
• DMARDs, like methotrexate, to slow down the immune system and keep RA from progressing
• Biologics to block parts of the immune system responsible for RA inflammation
• Janus kinase (JAK) inhibitors to inhibit the activity and response of certain enzymes that promote inflammation and overactivity of the immune system
• Corticosteroids to reduce inflammation for periods when RA flares up

Physical and occupational therapy can help manage aspects of your daily life with RA. A physical therapist can give you information about safe exercises to keep your joints strong and mobile. An occupational therapist can teach you how to safely handle daily tasks, such as cooking or job tasks, and suggest assistive devices that might help you.  

Joint replacement surgery is done in cases in which pain and inflammation have become extremely difficult or if joints are severely damaged. Surgery can dramatically improve a person’s mobility and reduce pain.  

Prevention

MS and RA are not preventable conditions. If you have someone with a family history of MS, RA, or another autoimmune disease, talk to your healthcare provider about this risk factor and others you may have.  

Even if you have an increased genetic risk for MS or RA, it is impossible to predict whether you will have one of these conditions in the future. Fortunately, it is possible to slow down disease progression in both conditions and prevent flare-ups.

Summary

Multiple sclerosis and rheumatoid arthritis are both autoimmune diseases. They result when a person’s immune system malfunctions and starts attacking healthy tissues. With MS, immune system attacks are targeted at the myelin sheath. In RA, the linings of the joints are targeted.  

There is no cure for MS or RA, and both of these conditions can worsen over time. Early diagnosis and treatment are crucial for slowing down these conditions and reducing the potential for permanent damage. Neither disease is preventable, and there is no way of knowing who may develop MS or RA.  

A Word From Verywell 

If you are diagnosed with MS or RA, you should meet with your healthcare provider regularly. These are aggressive conditions, and they need regular monitoring and strong medicines, so they don’t become life-threatening. Consistent healthcare visits can help improve your outlook and preserve your quality of life.  

These conditions also affect vital organs, mainly the eyes. Make sure you are getting your eyes checked annually to look for changes or problems before they worsen.