What Is Ankylosing Spondylitis?

Ankylosing spondylitis (AS) is an autoimmune condition and a type of inflammatory arthritis that primarily affects the spine, among other joints. Inflammation in the joints of the spine can cause back pain and stiffness. As the disease progresses, inflammation can change the structure of your joints, affect your posture, limit your range of motion, and reduce your quality of life.

The exact cause of AS is not fully understood, but researchers believe a combination of genetic and environmental risk factors play a role in the development of the condition. If you think you may have symptoms of AS, it’s a good idea to get tested. 

During your appointment, your healthcare provider will learn about your medical history, perform a physical exam, and order additional tests (e.g., blood, imaging, or lab tests) to confirm an AS diagnosis. While there is no cure for AS, treatment can help you manage your symptoms and improve your daily life. 


Symptoms of AS vary from person to person and can range from mild to severe. For most people with AS, symptoms usually appear before age 45 and develop gradually over time. Symptoms tend to come and go, as many people with AS experience flares (or, periods when symptoms worsen).

Common symptoms of AS include:

  • Back pain and stiffness: The hallmark symptom of AS, spinal or back pain and stiffness are usually worse in the morning or after long periods of inactivity. 
  • Joint pain: Inflammation can cause pain and stiffness in other joints, including the hips, shoulders, neck, ribs, knees, and feet. 
  • Enthesitis: Swelling and tenderness in the entheses (where your tendons and ligaments attach to your bone), mostly in the heels, soles of the feet, and hips.  
  • Fatigue: Inflammation and the side effects of some medications can lead to chronic fatigue. 
  • Uveitis: A form of inflammation in your eyes that can cause redness, pain, light sensitivity, and vision changes. 
  • Limited mobility: As the spine and other joints become more inflamed, the spinal vertebrae (a series of small bones) can become stiff, causing a reduction in your range of motion and limiting your ability to perform daily tasks. 

If your condition progresses, you may also experience more serious symptoms such as:

Causes and Risk Factors 

Ankylosing spondylitis is an autoimmune condition, meaning the immune system attacks healthy cells in the spine by mistake. As a result, your immune system produces inflammation which causes the physical symptoms in your body. Like other autoimmune conditions, researchers don’t know the exact cause of the condition. However, they suspect that a combination of genetic and environmental factors may be to blame. 

People who have a family history of AS are more likely to develop this condition. Experts believe that inheriting certain genes can contribute to your likelihood of getting the condition and the severity of your symptoms. 

Currently, researchers have identified over 60 genes associated with the disease. The most common gene in people with AS is the HLA-B27 gene. Keep in mind: not everyone who has the HLA-B27 gene will develop the disease. This finding suggests that genes alone don’t cause AS, but the interaction between your genetic makeup and environmental factors can trigger symptoms.

In addition to genetics, there are several risk factors that researchers believe can increase your risk of AS. These factors include: 

  • Age: Most people with AS receive their diagnosis between the ages of 17 and 45
  • Ethnicity: AS is more common in white people of northern European descent
  • Smoking: Smoking cigarettes can lead to a more rapid onset of AS symptoms
  • Mechanical stress: Wear and tear on the joints can trigger your genes to produce inflammation
  • Previous infection: A history of certain bacterial or fungal infections may trigger immune system dysfunction and lead to the onset of AS symptoms 
  • Inflammatory bowel disease: Having Crohn's disease, ulcerative colitis, or another inflammatory disease increases the risk of AS-related inflammation

It’s important to note that having one or more risk factors doesn’t guarantee that you’ll get AS—it just means that it may increase your risk of developing symptoms. 


Diagnosing AS requires some detective work on the part of your healthcare provider because the condition can mimic symptoms of other arthritis-related conditions. During your first appointment, your provider will ask about your symptoms, your personal and family medical history, and your lifestyle habits. 

They will likely also perform or order a variety of diagnostic tests, including:

  • Physical exam: Measure your vitals, check your spine for pain and tenderness, assess the range of motion in your joints, and examine your posture  
  • X-rays: Imaging scans that check for bone loss or damage, osteophytes (bony growths), and fusion (joining) of the spinal bones 
  • Magnetic resonance imaging (MRI): Takes detailed images of soft tissues in the body and looks for signs of inflammation in your joints
  • HLA-B27 genetic test: Blood test to check for the HLA-B27 gene, which is common in people with AS 


There is no cure for AS, but treatment can reduce pain and inflammation, slow disease progression, and help prevent complications (e.g., joint damage). Symptoms of AS vary from person to person—and it’s no different with treatment. Your treatment regimen will depend on your symptoms, severity of the condition, age, and lifestyle. 

Generally, your healthcare provider will recommend a combination of medications and therapies to help you manage symptoms. In rare and advanced cases of AS, your provider can work with a surgeon to identify if surgery will improve your condition and overall quality of life. 


There are several types of medications that you can use to treat AS. Because everyone responds to treatment differently, it may take trial and error until you find the right combination of drugs to control your individual symptoms. Medicines for treating AS include:

  • NSAIDs: Nonsteroidal anti-inflammatory drugs (NSAIDs) help control inflammation to reduce pain and stiffness. Some NSAIDs are available over-the-counter (OTC), like Advil (ibuprofen). But if your body doesn’t respond to OTC medication, your provider can prescribe your stronger NSAIDs. 
  • DMARDs: Disease-modifying anti-rheumatic drugs (DMARDs) suppress the immune system to reduce inflammation and pain. DMARDs are typically ineffective for back pain, but can help relieve pressure in the peripheral joints, such as the hips, knees, and ankles.
  • TNF inhibitors (TNFi): TNF inhibitors block tumor necrosis factor-alpha (TNF-a), a type of protein made by the immune system that causes inflammation. TNF inhibitors block the production of protein in your immune system to fight inflammation, manage symptoms, and slow down your disease progression.  
  • Interleukin-17 (IL-17) inhibitors: IL-17 inhibitors block your immune system from producing inflammation, which can reduce pain and swelling in the joints.
  • Corticosteroids: In some cases, your provider can prescribe steroid medications on a short-term basis to relieve joint pain.

Physical Therapy 

Physical therapy is an essential component of treating ankylosing spondylitis. Your provider will likely refer you to a physical therapist to help you learn ways to reduce symptoms via exercise. 

A physical therapist will work with you to develop a treatment plan based on your individual needs and goals. Generally, the goal of physical therapy is to help you reduce symptoms by increasing muscle strength and endurance, enhancing your breathing, and helping you maintain a healthy weight.

Exercises during your sessions may include one or more of the following:

  • Stretching 
  • Cardio workouts including walking or biking  
  • Weight lifting 
  • Balance exercises 


Some people with advanced AS may need surgery if they have severe pain, joint deformities, spinal fractures, or infections. Your healthcare provider will usually only recommend treatment if your symptoms are severe and other treatments haven’t improved your condition.

Generally, your primary care provider will consult with a surgeon or rheumatologist (a doctor who specializes in the joints, muscles, and bones) before telling you about your surgical options. 

If surgery is the right step for your, the most common surgical procedures for AS include: 

  • Hip replacement: If your hip joints are severely damaged and cause significant pain and loss of mobility, removing part of the hip joint and replacing it with a prosthetic joint can help improve mobility and reduce pain.
  • Laminectomy: A decompression surgery that takes pressure off the spinal cord and nerves to relieve weakness, tingling, and pain.
  • Osteotomy: During an osteotomy, your spinal bone may be cut and reshaped to correct deformities, improve posture, and help restore flexibility. 
  • Spinal fusion: A spinal fusion involves joining two or more spinal vertebrae (a series of small bones) to stabilize your spine and relieve severe back pain.

Preventing Ankylosing Spondylitis Flares

Living with ankylosing spondylitis means you may experience flares, or periods when your symptoms become more severe. Along with intense back pain, flares may cause extreme fatigue, mild fever, depression, and pain in other joints.

Fortunately, there are things you can do that may help prevent the frequency of AS flares: 

  • Exercise regularly 
  • Maintain good posture
  • Get uninterrupted sleep at night 
  • Quit smoking 
  • Manage stress through relaxation or breathing techniques 
  • Eat foods that help fight inflammation
  • Follow your treatment plan as prescribed 

If you notice that your flares are getting worse, get in touch with your healthcare provider. They can help you learn other prevention techniques or adjust your treatment plan to help you better manage your symptoms.

Co-occurring Conditions   

Co-occurring or comorbid conditions are conditions that you are more likely to get if you have AS. Approximately 80% of people with AS have one or more co-occurring conditions, including:

  • Heart disease: Chronic inflammation can affect the heart and increase the risk of heart attack, stroke, irregular heartbeat, atherosclerosis (high cholesterol), high blood pressure, and heart failure.
  • Inflammatory bowel disease (IBD): Evidence suggests a strong connection between gut inflammation and AS. About 10% of people with AS will develop a form of IBD within 20 years after diagnosis.
  • Depression: Living with AS can be difficult. Dealing with painful symptoms that hinder your daily life can lead to depressive thoughts and moods. Research suggests that inflammation and pain caused by AS can lead to symptoms of depression.
  • Osteoporosis: If AS progresses, you might experience bone loss or damage, which can increase your risk of developing osteoporosis (weak bones) and fractures.

Living With Ankylosing Spondylitis 

Living with ankylosing spondylitis can be as difficult as it is painful. If you notice that you have symptoms of AS or have a family history of the condition, it’s a good idea to be proactive about your health and see your healthcare provider. 

If you receive a diagnosis for AS, it’s essential that you follow your treatment plan. Because AS can affect each person differently, it may take some time to find a treatment regimen that is right for you—and that’s OK. 

The important thing is that you stay in touch with your provider and keep them updated about your symptoms and whether you think your medications or therapies are working. The good news is that research for AS remains ongoing, so experts are learning about more effective treatments. 

But in the meantime, taking your medications as prescribed, getting regular exercise, and managing stress levels can help control symptoms. Many people also find emotional support through in-person and digital support groups, spending time with their loved ones, and doing hobbies that they enjoy. With the right treatments and support, people with AS can expect to live full, happy lives. 

Was this page helpful?
Health.com 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. Spondylitis Association of America. Overview of ankylosing spondylitis.

  2. Spondylitis Association of America. Examining flares in spondyloarthritis.

  3. Spondylitis Association of America. Most common symptoms.

  4. Yu DT, van Tubergen A. Clinical manifestations of axial spondyloarthritis (ankylosing spondylitis and nonradiographic axial spondyloarthritis) in adults. In: Post TW. UpToDate. UpToDate; 2022.

  5. Spondylitis Association of America. Possible complications: How is a person affected?

  6. Spondylitis Association of America. Genetics of ankylosing spondylitis.

  7. Spondylitis Association of America. Ethnicity and disease severity in ankylosing spondylitis.

  8. Kaut IK, Abourazzak FE, Jamila E, Sènami FA, et al. Axial spondyloarthritis and cigarette smoking. Open Rheumatol J. 2017;11:53-61. doi:10.2174/1874312901711010053

  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. Abdelaziz MM, Ismail N, Gamal AM, et al. Comparative analysis between ankylosing spondylitis and axial psoriatic arthritis patients. The Egyptian Rheumatologist. 2022;44(1):25-29. doi:10.1016/j.ejr.2021.07.006

  11. National Institute of Arthritis and Musculoskeletal and Skin Diseases. Diagnosing ankylosing spondylitis.

  12. Spondylitis Association of America. Medications used to treat ankylosing spondylitis.

  13. Spondylitis Association of America. A prescription for exercise.

  14. Spondylitis Association of America. Exercise.

  15. Zakaryan A, Ginosyan K. Perioperative management of patients with ankylosing spondylitis undergoing spine surgery. Front Pharmacol. 2020;11:1017. doi:10.3389/fphar.2020.01017

  16. Ward MM. Increased rates of both knee and hip arthroplasties in older patients with ankylosing spondylitis. J Rheumatol. 2019;46(1):31-37. doi:10.3899/jrheum.171316

  17. MedlinePlus. Laminectomy.

  18. Xin Z, Zheng G, Huang P, et al. Clinical results and surgery tactics of spinal osteotomy for ankylosing spondylitis kyphosis: Experience of 428 patients. J Orthop Surg Res. 2019;14(1):330. doi:10.1186/s13018-019-1371-y

  19. MedlinePlus. Spinal fusion.

  20. Redeker I, Callhoff J, Hoffmann F, et al. The prevalence and impact of comorbidities on patients with axial spondyloarthritis: Results from a nationwide population-based study. Arthritis Res Ther. 2020;22(1):210. doi:10.1186/s13075-020-02301-0

  21. Ozkan Y. Cardiac involvement in ankylosing spondylitis. J Clin Med Res. 2016;8(6):427-430. doi:10.14740/jocmr2488w

  22. Spondylitis Association of America. Predicting Crohn’s disease in those with ankylosing spondylitis.

  23. Webers C, Vanhoof L, Leue C, Boonen A, Köhler S. Depression in ankylosing spondylitis and the role of disease-related and contextual factors: A cross-sectional study. Arthritis Res Ther. 2019;21(1):215. doi:10.1186/s13075-019-1995-7

Related Articles