Ankylosing spondylitis
Ankylosing spondylitis (AS) is a condition that mainly affects the spine. The joints of the neck, back and pelvis become inflamed, causing pain and stiffness. Other joints, such as the hips and shoulders, and other areas of the body such as the eyes, skin, bowel and lungs, can also be involved. Symptoms of AS usually begin between the ages of 15 and 45 years.