Ankylosing Spondylitis (AS) is an inflammatory condition of the lower back usually associated with stiffness and pain coming from the lower back region and hips. It commonly arises in people under 40. It is usually diagnosed by a blood test and X Rays or MRI. The exact cause is not known but there may be a hereditary factor. AS can also affect other organs of the body. Physiotherapy can help with increasing movement and reducing pain.