Ankylosing spondylitis is a chronic inflammatory disease that affects approximately 350,000 Americans. It is a form of arthritis. The disease most often develops in the spine, but it can also affect the knees, hips, shoulders, and other joints. It can also cause health problems involving the eyes. Some cases of ankylosing spondylitis may even affect the heart or lungs. Treatment for ankylosing spondylitis often involves physical therapy, exercise, and medications. There is no cure for the condition, but treatment can help manage its symptoms and may slow its progression in some cases.