Arthritis Health Center

What is ankylosing spondylitis?

Ankylosing spondylitis (say "ang-kill-LOH-sing spawn-duh-LY-tus") is a long-term form of arthritis that most often occurs in the spine . It can cause pain and stiffness in the low back, middle back, buttocks, and neck, and sometimes in other areas such as the hips, chest wall, or heels. It can also cause swelling and limited motion in these areas. This disease is more common in men than in women.

There is no cure, but treatment can control symptoms and prevent the disease from getting worse in most cases. Most people are able to do their normal daily activities and can still work.

This disease can cause several other problems. You may have redness and pain in the colored part of your eye (iritis). You also may have trouble breathing as your upper body begins to curve and your chest wall begins to stiffen.

What causes ankylosing spondylitis?

The cause is unknown, but it may run in families. Most people with ankylosing spondylitis are born with a certain gene, HLA-B27. But having this gene does not mean that you will get the disease.

Research suggests that bacterial infections and your environment may have roles in causing this disease.

What are the symptoms?

This disease causes mild to severe pain in the low back and buttocks that is often worse in early morning. Some people have more pain in other areas, such as the hips or heels. The pain usually gets better slowly as you move around and are active. Ankylosing spondylitis most often begins anywhere from the teenage years through the 30s.

It gets worse slowly over time as swelling of the ligaments, tendons, and joints of the spine causes the bones of the spine to join, or fuse , together. This leads to less range of movement in the neck and low back.

As the spine fuses and stiffens, the neck and low back lose their normal curve. The middle back curves outward. This can keep you in a bent-forward position and may make it hard for you to walk.

As the small joints that connect the ribs and collarbone to the breastbone get inflamed, you may find that it?s harder for you to breathe. Other parts of the body, such as your eyes and your other joints, may also swell. Sometimes the disease affects the lungs, the heart valves, the digestive tract, and the major blood vessel called the aorta.

How is ankylosing spondylitis diagnosed?

The early signs of this disease-dull pain in the low back and buttocks-are common. Your doctor will ask about your symptoms and if they have become worse over time. Your doctor will also ask if you have a family history of this joint disease or others like it.