Ankylosing spondylitis (AS) is an inflammatory disease that causes pain in the spine, pelvis, and joints throughout the body. It is a chronic (lifelong) disease, and it is hereditary. AS causes abnormal bone growth, and causes joints to fuse (grow together) in the spine and in the sacroiliac joints (located between each hip and the pelvis). Vital organs like the heart, lungs, and eyes may also be affected. Although there is currently no cure for AS, proper treatment, including physical therapy, can help decrease the pain and stiffness associated with the disease.