Ankylosing spondylitis is a form of arthritis of the lower back caused by inflammation. Symptoms include pain and stiffness in the back and hips and sometimes the neck and shoulders that will be worse during sleep and rest.

What is ankylosing spondylitis?

Summary

"Ankylosing" means a joint has become stiff and fixed in one position due to injury or disease. "Spondylitis" means inflammation in the joints of the spine. In ankylosing spondylitis, inflammation has damaged the vertebrae of the low back and caused a form of arthritis, leaving the lower spine inflexible.

Symptoms include pain and stiffness in the back and hips, and sometimes in the neck and shoulders. The pain will be worse during sleep and rest.

The diagnosis is made through physical examination and X-rays. Early treatment can help manage the symptoms, prevent complications, and improve quality of life. Treatment involves non-steroidal anti-inflammatory drugs (NSAIDs); new forms of biologic medications; physical therapy; and, in some cases, surgery to repair damaged joints.

Recommended care

You should visit your primary care physician, where, based on clinical exam, blood tests, and x-rays, your doctor will likely recommend physical therapy, medications or a referral to a specialist.

Ankylosing spondylitis symptoms

There are a few main symptoms that affect the majority of people with this condition. It's likely that pain felt anywhere in the body will come on gradually, get worse with rest, and better with activity.

Main symptoms

The main symptoms of ankylosing spondylitis include pain anywhere along the back or spine.

Back pain: Ankylosing spondylitis is primarily a disease of the spine, and will likely cause back pain. The back pain is often gradual, gets worse at night and while lying still, and improves with exercise and activity. Back pain is usually worse in the morning.
Neck pain: Neck pain occurs in about half of people with this condition due to inflammation of the upper part of the spine.
Difficulty moving the back and abnormal back posture: People who have advanced ankylosing spondylitis may have difficulty moving or bending their back. This difficulty occurs because long-term inflammation can cause the spine to fuse together. Fused bones may cause abnormal posture or a "hunchback" position, in which you bend forward.

Ankylosing spondylitis quiz

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Joint/Musculoskeletal pain

You may experience pain in the major joints or small appendages, such as the fingers.

Hip, groin, and/or buttock pain: Hip, groin, or buttock pain may occur due to inflammation of the hip joints.
Pain in other joints: Affected joints may include the knees, ankles, shoulders, or the chest. In rare cases, you may experience jaw pain that gets worse with chewing, due to inflammation of the jaw joint.
Pain at sites of tendon and ligament insertions ("enthesitis"): About one-third of people with ankylosing spondylitis will experience pain and inflammation at sites of tendon and ligament insertions, known as enthesitis. Tendons and ligaments are tough, fibrous bands that connect muscles to bone and bone to bone, respectively. Inflammation of these attachments may cause pain in the back of the ankle, the feet, the shoulders, and the center of the chest.
Painful swelling of the fingers or toes ("dactylitis"): In rare cases, people with ankylosing spondylitis may experience painful finger swelling or toes, known as "dactylitis."

Other symptoms

Additional symptoms may include the following.

Eye pain, light sensitivity, and blurry vision: Some people with ankylosing spondylitis may experience eye pain, light sensitivity, or blurry vision, usually in one eye. These episodes may last for several weeks and can recur.
Abdominal pain and/or bloody stools: Some people with ankylosing spondylitis may experience abdominal pain or bloody stools, due to bowel inflammation.
Itchy, scaly patches of skin: Some people with ankylosing spondylitis may develop itchy, scaly patches of skin, known as psoriasis. These areas of skin are usually raised and covered with a silvery scale that can flake off.

Complications

In addition to these symptoms, ankylosing spondylitis can increase the risk of developing diseases of other organs including the heart, lungs, or kidneys.

Ankylosing spondylitis causes

The exact cause of ankylosing spondylitis is unknown. It is thought to be an inherited, abnormal immune response that is triggered following damage to the lining of the intestines. As discussed, ankylosing spondylitis is an inflammatory joint disease (arthritis) of the spine and sometimes other joints in the body.

Changes in gut bacteria

The composition of gut bacteria in people with ankylosing spondylitis has been found to be different from the composition of gut bacteria in people who do not have ankylosing spondylitis. Exactly how gut bacteria leads to the development of ankylosing spondylitis is unclear, but it is thought that certain gut bacteria may be able to break down the gut lining and pass into the bloodstream, which they can induce inflammation throughout the body.

Chemical signals that increase inflammation

Several chemical signals that increase inflammation are thought to contribute to the development of ankylosing spondylitis, including interleukins, which are signaling molecules used by the immune system. Interleukin (IL)-23 is believed to activate a certain type of immune system cell that travels to the bones and joints and causes inflammation, contributing to many of the symptoms seen in ankylosing spondylitis.

Genetic factors

The most important genetic factor involves a gene called HLA-B27, which encodes for a marker seen on certain immune system cells. It is thought that certain variants of the HLA-B27 gene may contribute to the development of ankylosing spondylitis by causing inflammation and/or triggering the immune system to attack one's own body. Other genetic changes have also been associated with ankylosing spondylitis, many of which are involved with the immune system.

Who is most often affected?

Ankylosing spondylitis usually affects:

People before the age of 45
It is more common among men
People with a family history of ankylosing spondylitis
People who have a family history, as well as a history of intestinal damage from illness, are the most susceptible to developing ankylosing spondylitis, regardless of age.

Treatment options and prevention for ankylosing spondylitis

Ankylosing spondylitis is a long-term condition that may require a combination of lifestyle changes, medications, and possible surgery to treat. Symptoms will usually wax and wane over many years. Most people with mild forms of the disease can maintain full function and live productive lives, while others may develop more severe ankylosing spondylitis symptoms that may be disabling.

Exercise and lifestyle modification

Exercise is an important part of management for ankylosing spondylitis. Most people will benefit from a structured exercise regimen, especially a supervised exercise program or formal physical therapy. In addition, quitting smoking has been shown to improve outcomes in ankylosing spondylitis.

Medications to reduce inflammation

Physicians will usually recommend starting with milder medications and increasing to more potent medications as needed. To start, medications such as ibuprofen or celecoxib (Celebrex) may be enough for many people. Newer potent medications include adalimumab (Humira), infliximab (Remicade), etanercept (Enbrel), and sulfasalazine (Azulfidine). Steroid medications such as prednisone may be used for short time periods but are usually not recommended for long-term treatment due to side effects.

Further medical treatments

If the previous methods do not provide relief, your physician may recommend the following.

Steroid injections: When administered directly into joints that are actively inflamed and painful, steroid injections may provide relief for some people.
Surgery of the spine or other joints: People with ankylosing spondylitis near the neck may benefit from surgery to fuse the bones of the spine to improve stability. Those with severe hip pain may benefit from total hip replacement, in which the hip joint is removed and replaced with a prosthetic joint.

When to seek further consultation for ankylosing spondylitis

You should see your physician if you experience symptoms of ankylosing spondylitis, such as:

Back, neck, or hip pain
Difficulty moving the back
Abdominal pain
Eye pain

He or she can order laboratory and imaging tests to determine if you have ankylosing spondylitis and then offer the appropriate treatment.

Questions your doctor may ask to determine ankylosing spondylitis

Any fever today or during the last week?
Are you having difficulty concentrating or thinking through daily activities?
Do you currently smoke?
Do you have trouble sleeping?
How fatigued are you?

Self-diagnose with our free Buoy Assistant if you answer yes on any of these questions.

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The stories shared below are not written by Buoy employees. Buoy does not endorse any of the information in these stories. Whenever you have questions or concerns about a medical condition, you should always contact your doctor or a healthcare provider.

Jeffrey M. Rothschild, MD, MPH.

Associate Professor of Medicine, Brigham and Women’s Hospital

Dr. Rothschild has been a faculty member at Brigham and Women’s Hospital where he is an Associate Professor of Medicine at Harvard Medical School. He currently practices as a hospitalist at Newton Wellesley Hospital. In 1978, Dr. Rothschild received his MD at the Medical College of Wisconsin and trained in internal medicine followed by a fellowship in critical care medicine. He also received an MP...

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