"Ankylosing spondylitis is a Rheumatic disease that causes arthritis of the spine and sacro iliac joint and can cause inflammation of the eyes, lungs and heart valves. It varies from intermittent episodes of back pain that occur through out life to 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 "

- American college of Rheumatology