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Ankylosing Spondylitis (AS)

About Ankylosing Spondylitis (AS)

In this section, you or a loved one can find out more about medical treatments, research studies and practical information about ankylosing spondylitis (AS). Read on to find answers to some of your questions as well as links to other information. Being informed is an important first step towards becoming an active decision-maker in your care plan.

What Is Ankylosing Spondylitis?

Ankylosing spondylitis is a form of arthritis, one of a group of conditions that causes chronic inflammation most commonly in the spine (back) and sacroiliac joints (where the lower back/tail bone meets the bones that make up either side of the pelvis). Ankylosing spondylitis causes inflammation, pain and stiffness mainly in the spinal joints, but can affect tissues, organs and joints throughout the body. Symptoms of AS can range from relatively mild to severe, may come and go, and you may experience flare-ups when your symptoms are worse than usual. AS most often begins before the age of 40 and occurs with approximately equal frequency in both men and women1.

There is no cure for AS so treatment focuses on controlling symptoms and preventing disability.

What Causes Ankylosing Spondylitis?

The exact cause of AS is not known, but genetics, immune system dysfunction and environmental factors may each contribute to the development of AS. A specific gene called HLA-B27 has been associated with a higher risk of developing AS. However, not everyone who has this gene will develop AS, which suggests that environmental factors may have a role.

Which body parts are affected and how?

Ankylosing spondylitis can affect people differently, with varying symptoms ranging from mild to severe. It is impossible to predict how it will affect you. In AS, back pain and stiffness are chronic (lasting more than 3 months), with pain often starting in the lower part of the back. In addition to the lower back, AS can affect other parts of the body, such as the ribs, feet, upper back or neck. AS-associated pain and stiffness are a result of inflammation and may have features that can help distinguish AS back pain from an injury or other mechanical back pain. For example, AS pain and stiffness will not improve and may worsen with rest, and can often be worse first thing in the morning or during the night. In contrast, pain from AS will often feel better with physical activity.

As AS progresses, inflammation involving the spine can lead to fusion of the spinal joints. In more severe cases, this can result in a forward-stooped posture.

In some patients, AS causes pain and swelling in joints other than the spine, such as the knees, shoulders and hips2.

In addition to the joints, AS can cause inflammation in the entheses, which is where tendons and ligaments insert into the bone – this is called enthesitis. The following are common locations where entheses are affected by AS:

●        Back of the heels
●        The bottom of the feet
●        The outside of the hips
●        Where the breast bone attaches to ribs
●        Within the spine

AS-related inflammation can also affect tissue within the eye, which results in what is called uveitis.

Are there ways to treat AS symptoms?

Yes, as symptoms vary from person to person, so do treatment options. Your doctor can explain the differences, benefits and side effects of each. It is likely that you will try different therapies or combinations before finding what works best for you. Treatment options may include:

Medical Treatments

The general approach to treating AS is to reduce inflammation and thus reduce symptoms and maintain spinal flexibility and posture in order to reduce limitations to daily activities3.

Four types of medication are used to treat the symptoms of arthritis in AS:

Non-steroidal anti-inflammatory drugs (NSAIDs) are a class of medications that can be used to treat the inflammation, and thus the pain and stiffness of AS. NSAIDs do not control the disease; they only treat symptoms.

The most common side effects associated with NSAID use are indigestion, heartburn, and stomach and abdominal pain. They can also alter the protective lining of the stomach and gut, making you susceptible to ulcers and bleeding, so you should avoid taking more than one NSAID at a time. As with all the medical treatments, before starting any NSAID, discuss with your doctor if this is the appropriate treatment for you.

Disease-modifying anti-rheumatic drugs (DMARDs) are prescription medications that may relieve symptoms of joint pain and swelling in AS. DMARDs are not effective for treating pain and stiffness in the spine. Sulfasalazine is the most commonly used DMARD in AS. Sometimes weeks or months of treatment may pass before there is a noticeable difference in pain and joint swelling. Sulfasalazine can cause nausea and abdominal discomfort when treatment is first started4. People who are allergic to sulfa drugs should not take sulfasalazine.
Corticosteroids work by reducing inflammation. Corticosteroids can be injected directly into a joint or the area where tendons and ligaments insert into bone (enthesis). The use of oral corticosteroids is not recommended in AS5.
Biologic response modifiers, or “biologics” for short, are medications specifically designed to target your body’s immune system. Biologics are also used to decrease inflammation and ease the pain and stiffness associated with AS.
Lifestyle tips

Incorporating healthy lifestyle habits into your AS treatment plan can help you to manage AS symptoms and limit your activity restrictions.

Smoking has been associated with more severe AS signs and symptoms6.
Regular physical activity and exercise can help maintain spinal mobility and posture. Consult your doctor before starting any exercise programme. Consulting a physiotherapist who is experienced in treating AS patients may also be useful in determining the best exercise plan for you.
Maintaining a healthy body weight can minimise strain and pressure on your joints. Adopting healthy eating habits can help you to sustain a healthy weight and leave you feeling more energetic.

Protect your spine and joints from damage by making a few changes to daily activities. Ways to protect your spine and joints include:

  • Avoid movements that put stress on your spine, such as bending forward from the waist
  • To help keep good alignment in your spine, sleep on a firm mattress and use special neck support or pillows
  • Be conscious of good posture during the day while standing, sitting or during necessary activities such as walking or climbing stairs.
  • When partaking in what can be prolonged or repetitive activities, such as using a computer, be mindful of the position of your neck, wrists and lower back. Ensure that they are in relaxed and neutral positions – this will help to avoid undue stress on your spine.

Both heat and cold can help reduce arthritis pain. The choice of using heat or cold should be based on how it makes you feel.

  • Heat: A stiff back and joints may benefit from application of heat. A warm shower or bath, or warm compress may help relax the muscles and relieve stiffness and pain in your joints and back. Caution should be used to prevent burns.
  • Cold: For swollen joints applying a cold compress (or a plastic bag of ice cubes wrapped in a towel) for about 15 minutes can help constrict blood flow and decrease the pain and swelling. Caution should be used to prevent circulation problems or frostbite.

Please note that the information on this website is intended for informational purposes only and should not be used as a substitute for seeking medical advice or treatment from a healthcare professional. You should not use this information to diagnose or treat a medical condition or health problem. Speak to a healthcare professional if you have any questions about your health, medical condition, symptoms or treatment options.


1 Ernst Feldtkeller, Dr. rer. nat.,* Jane Bruckel, BSN, RN,† and Muhammad Asim Khan, MD, FRCP‡ Scientific contributions of ankylosing spondylitis patient advocacy groups.

Current Opinion in Rheumatology 2000, 12:239–247

2-3 Ankylosing Spondylitis and Axial Spondyloarthritis Joel D. Taurog, M.D., Avneesh Chhabra, M.D., and Robert A. Colbert, M.D., Ph.D

N Engl J Med 2016;374:2563-74.


5 Ann Rheum Dis 2011;70:905–908. & Ann Rheum Dis 2006;65:442–452.

6 Xavier Guillot, Clément Prati, Daniel Wendling. (2014) Vitamin D and spondyloarthritis. Expert Review of Clinical Immunology 10:12, 1581-1589.

Online publication date: 1-Apr-2015.

National Ankylosing Spondylitis Society

UK charity dedicated to supporting anyone affected by ankylosing spondylitis (AS)

Additional Resources to Explore:

Spondylitis Association of America (SAA) was founded in 1983 by people affected by spondyloarthritis. SAA was the first and remains the largest resource in the United States for people seeking information on AS and related diseases.

Mayo Clinic


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