Ankylosing spondylitis (AS) is an inflammatory joint disease that primarily affects the spine. As ankylosing spondylitis progresses, the vertebrae in the spine fuse together (ankylosis), causing the spine to be less flexible and may result in a hunched-forward posture. Signs and symptoms of ankylosing spondylitis may include pain and stiffness in your lower back and hips. Affected areas can include the joints between the base of your spine and pelvis, the joints between the vertebrae, the hip joints, and the shoulder joints. Up to 40 percent of individuals with ankylosing spondylitis will have eye inflammation that may cause eye pain, sensitivity to light and blurred vision. Other less common complications include restricted lung function and heart inflammation. Risk factors of ankylosing spondylitis include gender and age, as men develop ankylosing spondylitis more often than women and onset of symptoms typically occurs in late adolescence and early adulthood. The exact cause of ankylosing spondylitis is unknown, but it is believed that both genetic and environmental factors play a role. One genetic factor is the HLA-B gene, which provides instructions for making a protein that helps the immune system distinguish the body’s own proteins from foreign invaders (such as viruses and bacteria). Individuals who have the HLA-B27 variation of the HLA-B gene are at greater risk of developing ankylosing spondylitis. Your doctor may use a physical exam along with imaging tests and lab tests to diagnosis the condition. There is no cure for ankylosing spondylitis, but there are treatment options that can help decrease your pain and reduce your symptoms. Support groups are good resources for additional information. Contact a doctor if you or someone in your family has been diagnosed with ankylosing spondylitis to discuss the most current treatment options.