MS vs. Ankylosing Spondylitis: What Are the Differences?

Table of Contents
View All
Table of Contents

Despite both being autoimmune diseases, multiple sclerosis (MS) and ankylosing spondylitis (AS) are unrelated conditions. They rarely coexist, and they differ significantly in symptoms, diagnosis, and treatment.

In MS, the immune system attacks nerve fibers in the brain and spinal cord and their protective myelin covering. This may lead to neurological symptoms like numbness, weakness, and vision problems.

In AS, the immune system attacks the spine, including the sacroiliac joints, which connect your lower spine to your pelvis. Even though it's considered a type of arthritis, AS can also affect multiple other organs in your body, including your heart, eyes, skin, intestines, and kidneys.

This article will provide a brief overview of MS and AS. Key differences in symptoms, causes, diagnosis, treatment, and prevention between the two autoimmune diseases will be highlighted.

Doctor discusses diagnosis with patient

FatCamera / Getty Images


The symptoms of both MS and AS usually start in early adulthood. They range in severity from being a mild nuisance to being severe and debilitating. Apart from these general similarities, AS and MS are unique conditions.

Multiple Sclerosis

MS symptoms are neurological in nature because the disease only affects the central nervous system. Your central nervous system (CNS) consists of your brain, spinal cord, and the optic nerves of your eyes.

The specific symptoms a person with MS has depends on which nerve-signaling pathways are affected within the CNS.

Common MS symptoms include:

Ankylosing Spondylitis

People with AS initially experience lower-back pain from inflamed sacroiliac joints. This aching pain comes on gradually over a period of weeks to months and usually worsens with inactivity and improves with exercise.

Over time, the inflammation moves from the sacroiliac joints to the spinal joints. Chronic inflammation of the spine may eventually cause the bones within the spine to fuse or stick together, resulting in a rigid, immobile spine that is severely disabling.

Other symptoms of AS may include:

  • Inflammation and pain of the hip and shoulder joints
  • Swelling of the heels or elbows from enthesitis (inflammation of the site where tendons and ligaments attach to bone)
  • Systemic (whole-body) symptoms like fatigue or loss of appetite

In some cases, people with AS experience symptoms related to other organs besides the joints. For example, AS can damage the eyes, causing eye pain and blurry vision, or the heart, leading to heart failure or abnormal heart rhythms.


Ankylosing spondylitis is seen in 0.2%–0.5% of the U.S. population. A 2019 study estimated prevalence of MS to be about 0.35% of the U.S. population.


The exact cause of both MS and AS remains unknown. However, both diseases involve the immune system launching misguided attacks on healthy tissues in the body.

Multiple Sclerosis

Experts suspect that genetics and certain lifestyle factors, like vitamin D deficiency or obesity in early childhood, may play a potential role in the development of MS.

Hormones whose levels are higher in females, such as estrogen, probably also contribute, considering females are 2 to 3 times more likely to be diagnosed with MS than males.

Ankylosing Spondylitis

Like MS, AS onset is likely due to the interaction of multiple factors, including genes, lifestyle habits, and environmental exposures.

One gene variant known as HLA-B27 is positive in 90% of people diagnosed with AS. Experts have found other genes linked to AS as well, including a gene called the ERAP-1 gene. This gene codes for a protein involved in the normal functioning of the immune system.

Other factors that may influence AS development include:

  • Certain infections
  • Drug or toxin exposure
  • Bacterial changes within your gut
  • Mechanical stress to affected joints
  • Bowel inflammation


The diagnosis of both MS and ankylosing spondylitis can be challenging because there is no single test to determine if a person has the disease. Moreover, symptoms in both conditions can be subtle or nonspecific, which can delay the diagnosis for years.

The diagnostic process for both conditions involves obtaining results from a person's medical history, physical examination, and various blood and imaging tests. Results from these tests ultimately guide healthcare providers into ruling the disease in or out.

Multiple Sclerosis

When making a diagnosis of MS, a neurologist—a doctor who specializes in diseases of the nervous system—will ask you questions about your symptoms and perform a neurological exam.

Results from the following tests will also be evaluated:

Taking all the above information into account, your neurologist will determine if you meet the McDonald criteria—a formal set of guidelines intended to help neurologists diagnose MS accurately and timely.

The premise of the McDonald criteria is that it provides evidence of damage to the CNS at different dates and to different parts—referred to as "dissemination in time and space."

Ankylosing Spondylitis

A rheumatologist—a doctor who specializes in diseases of the joints and muscles—usually makes the diagnosis of AS. Your provider would start by asking you questions about your symptoms and performing a physical exam.

During the physical exam, your spine, hip, and sacroiliac joints will be moved around to assess for range of motion. Your joints will also be examined for signs of inflammation like warmth, swelling, and tenderness.

Results from these tests will also be gathered and carefully evaluated:

Keep in mind that you may be referred to another specialist if you are having non-joint-related symptoms. For instance, a condition called uveitis (inflammation of the uvea at the center of the eye) is a possible symptom of AS and can be diagnosed by an ophthalmologist—a doctor specializing in conditions of the eyes.


There is no cure for MS or AS. However, there are therapies that can help alleviate symptoms and medications that can improve the long-term outcomes of both diseases.

Multiple Sclerosis

Disease-modifying treatments (DMTs) in MS are intended to decrease the number and severity of MS relapses a person may experience and slow the natural course of the disease.

What Is a Relapse?

A relapse is a flare-up of new or worsening neurological symptoms confirmed by the appearance of a lesion (area of inflammation) in your brain or spinal cord.

There are numerous DMTs available, and they come in three different forms—injections, oral therapies, and intravenous (IV) infusions. Selecting a DMT requires careful discussion and depends on many factors, including how aggressive your disease is and the drug's safety profile.

Of note, DMTs do not treat relapses or specific MS symptoms, like bladder dysfunction, pain, or fatigue. MS relapses can be treated with a corticosteroid, like Solu-Medrol (methylprednisolone) or prednisone, whereas MS symptoms are treated with lifestyle changes, medications, and/or rehabilitation therapies.

Ankylosing Spondylitis

The treatment of AS involves both physical therapy and medication to ease pain and improve everyday functioning.

Depending on the specific symptoms and severity of a patient's AS, a physical therapy program often entails a combination of gentle range of motion and muscle stretching and strengthening exercises.

Two types of medications used to treat AS include:


MS and AS cannot necessarily be prevented. This is because there are factors that contribute to the diseases' development that are out of a person's control. These factors include genetic makeup and immune system response.

Nevertheless, there are some lifestyle changes that may be helpful in preventing or combating each disease.

Multiple Sclerosis

Lifestyle behaviors that may help prevent MS onset or reduce the severity/progression if you have already been diagnosed include:

  • Maintaining a healthy weight
  • Ensuring a sufficient vitamin D level
  • Avoiding smoking
  • Engaging in regular physical activity

Ankylosing Spondylitis

Lifestyle behaviors that can optimize your functioning and well-being while living with AS include:

  • Avoiding smoking and excess alcohol intake
  • Engaging in a regular exercise program (e.g., gentle stretching, balance, and muscle strengthening exercises)
  • Maintaining a healthy weight


While both multiple sclerosis and ankylosing spondylitis are autoimmune diseases, they are otherwise unrelated and rarely coexist. MS is a disease of the brain and spinal cord, whereas ankylosing spondylitis is a type of inflammatory arthritis that mainly affects the spinal and sacroiliac joints.

The therapies for each condition are also unique; although, treatment goals are similar (e.g., relieving symptoms and delaying disease progression).

Key Differences

  • Symptoms are variable (e.g., numbness or weakness)

  • Inflammation occurs in the brain and spinal cord

  • Diagnosed by a neurologist

  • Treated with DMTs and symptom-targeted therapies

  • Hallmark symptom is back pain and stiffness

  • Inflammation occurs mostly in the sacroiliac/spinal joints

  • Diagnosed by a rheumatologist

  • Treated with exercise, NSAIDs, and sometimes a TNF blocker

Frequently Asked Questions

  • Is multiple sclerosis related to ankylosing spondylitis?

    No. Multiple sclerosis and ankylosing spondylitis are not related. The only common ground they share is that both are autoimmune diseases.

  • Can ankylosing spondylitis affect your brain?

    Research suggests that patients with AS may be more susceptible to thinking and memory problems. It's unclear whether this is due to a direct effect of AS on the brain or some other factor like medication or impaired social/physical activity as a result of the disease.

  • Are ankylosing spondylitis and MS autoimmune diseases?

    Yes. Ankylosing spondylitis and MS are autoimmune diseases. They develop as a result of the body's immune system targeting and attacking healthy tissues.

  • What things can worsen your MS or ankylosing spondylitis?

    Certain unhealthy lifestyle habits can worsen your MS or AS. For instance, smoking is linked to MS progression and a worsened disease state in AS. Also, obesity is associated with a worse clinical outcome in both MS and AS.

13 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.
  1. National Multiple Sclerosis Society. MS symptoms

  2. Taurog JD, Chhabra A, Colbert RA. Ankylosing spondylitis and axial spondyloarthritis. N Eng J Med. 2016;374(26):2563-74. doi:10.1056/NEJMra1406182

  3. Ozkan Y. Cardiac involvement in ankylosing spondylitis. J Clin Med Res. 2016;8(6):427-30. doi:10.14740/jocmr2488w

  4. Johns Hopkins Arthritis Center. Ankylosing spondylitis.

  5. Wallin MT, Culpepper WJ, Campbell JD, et al. The prevalence of MS in the United States: A population-based estimate using health claims data. Neurology. 2019;92(10):e1029-e1040. doi:10.1212/WNL.0000000000007035

  6. Harroud A, Mitchell RE, Richardson TG, et al. Childhood obesity and multiple sclerosis: A Mendelian randomization study. Mult Scler. 2021;27(14):2150-2158. doi:10.1177/13524585211001781

  7. Harbo HF, Gold R, Tintoré M. Sex and gender issues in multiple sclerosisTher Adv Neurol Disord. 2013;6(4):237-248. doi:10.1177/1756285613488434

  8. Akassou A, Bakri Y. Does HLA-B27 status influence ankylosing spondylitis phenotype? Clin Med Insights Arthritis Musculoskelet Disord. 2018;11:1179544117751627. doi:10.1177/1179544117751627

  9. Simone D, Al mossawi MH, Bowness P. Progress in our understanding of the pathogenesis of ankylosing spondylitis. Rheumatology (Oxford). 2018;57(suppl_6):vi4-vi9. doi:10.1093/rheumatology/key001

  10. National Multiple Sclerosis Society. Updated McDonald criteria expected to speed the diagnosis of MS and reduce misdiagnosis.

  11. McGinley MP, Goldschmidt CH, Rae-Grant AD. Diagnosis and treatment of multiple sclerosis: A reviewJAMA. 2021;325(8):765-779. doi:10.1001/jama.2020.26858

  12. Vitturi BK, Suriano ES, Pereira de Sousa AB, Torigoe DY. Cognitive impairment in patients with ankylosing spondylitis. Can J Neurol Sci. 2020;47(2):219-225. doi:10.1017/cjn.2020.14

  13. Maas F, Arends S, Van der veer E, et al. Obesity Is common in axial spondyloarthritis and is associated with poor clinical outcome. J Rheumatol. 2016;43(2):383-7. doi:10.3899/jrheum.150648

By Colleen Doherty, MD
 Colleen Doherty, MD, is a board-certified internist living with multiple sclerosis.