Ankylosing Spondylitis

Source: MedlinePlus Health Topics, U.S. National Library of Medicine

Last synced 8/9/2026Status: primary verified

What is ankylosing spondylitis? Ankylosing spondylitis (AS) is a type of arthritis of the spine. It causes inflammation (swelling) between your vertebrae (the bones that make up your spine) and the joints between your spine and pelvis. AS inflammation can cause stiffness and make it difficult to move and bend. Symptoms of AS can range from mild to severe back pain. Over time, AS can fuse (grow together) your vertebrae, limiting movement and causing a hunched posture. In some people, AS can affect other joints or body parts. There is no cure for AS, but early treatment can help manage symptoms, slow down the disease, and help you lead a more productive life. Who is more likely to get ankylosing spondylitis? Ankylosing spondylitis usually starts before age 45. Early symptoms may begin between the ages of 15 and 30. Your chance of developing AS can also increase if: You're a man. AS is more common and severe in men. You have a family history. If a member of your family has AS, you're more likely to get the disease. You have other medical conditions that may increase your risk of getting AS. These include Crohn's disease , ulcerative colitis , or psoriasis . What causes ankylosing spondylitis? No one knows what causes ankylosing spondylitis, but the environment and genes likely play a role. Your genes are parts of DNA in your cells that are passed down from your parents. Certain genes may increase your risk of getting the disease, but not everyone with these genes gets AS. What are the symptoms of ankylosing spondylitis? AS affects people differently. The most common symptom is pain and stiffness in the lower back and/or hips. The pain is usually worse during the night or after sitting for a long time. Over time, AS may progress to other areas of your spine or body. Symptoms may depend on which areas of your body the disease affects. Some people have symptoms that come and go. Others may have severe, ongoing pain. Other symptoms of ankylosing spondylitis may include: Pa

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This information is for general education and is not medical advice. Always talk to a licensed U.S. clinician about your situation, medications, or treatment decisions.