Ankylosing spondylitis (AS) is a rheumatic disease that causes arthritis of the spine and sacroiliac joints and can cause inflammation of the eyes, lungs, and heart valves.
It varies from intermittent episodes of back pain that start in early adulthood sand continue throughout life to a severe chronic disease that attacks the spine, peripheral joints and other body organs, resulting in severe joint and back stiffness, loss of motion and deformity as life progresses.
AS is one of a group of diseases that attack the spine called spondylarthropathies. In addition to AS, these diseases include reactive arthritis (Reiter’s syndrome), some cases of psoriatic arthritis and arthritis associated with inflammatory bowel disease.
As the inflammation subsides, bone grows out from both sides of the vertebrae, resulting in the bones of the spine becoming fused (joined together). This stiffening is called ankylosis. This condition is not common in men.