Health topic · Immunology & Rheumatology
Ankylosing Spondylitis
MedlinePlus, National Library of Medicine · Retrieved 2026-10-13
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…
Reference details
- MedlinePlus topic groups
- Bones, Joints and Muscles; Immune System
- Also called
- Rheumatoid spondylitis
- MeSH terms
- Spondylitis, Ankylosing
- XML release date
- 10/13/2026 02:30:36
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:
• Pain, stiffness, and inflammation of the joints.
• Difficulty taking a deep breath. This could occur if the joints connecting the ribs are affected.
• Changes in vision.
• Fatigue.
• Loss of appetite.
• Weight loss.
• Skin rashes, such as psoriasis.
• Abdominal (belly) pain and loose stools (poop).
How is ankylosing spondylitis diagnosed?
There is no single test for ankylosing spondylitis. To find out if you have AS your health care provider may:
• Ask about your medical history, including your symptoms.
• Ask about your family health history, including relatives who have had AS.
• Do a physical exam.
• Order blood tests or imaging studies.
What are the treatments for ankylosing spondylitis?
AS has no cure, but treatment may help relieve symptoms, maintain posture, and slow down the disease. Since other parts of your body can be affected by AS, you will likely work with a team of health care professionals for tests, diagnosis, and care.
Treatment usually includes medicine to help relieve symptoms and keep the disease from getting worse, as well as physical therapy to improve mobility. If AS is severe, surgery may be needed.
You can help manage your AS symptoms if you:
• Exercise
• Monitor your symptoms
• Manage your stress
• Use assistive devices as needed
• Follow a healthy diet
• Stop smoking, or don't start
NIH: National Institute of Arthritis and Musculoskeletal and Skin Disease
Sources and reuse
- Original MedlinePlus page
- Rheumatoid Arthritis
- Ankylosing Spondylitis
- Ankylosing spondylitis: MedlinePlus Genetics
- ClinicalTrials.gov: Spondylitis, Ankylosing
- National Institute of Arthritis and Musculoskeletal and Skin Diseases
- Ankylosing Spondylitis
- Public domain — NLM summaries
Original source summary. Follow the source links for additional information.
Retrieved: 2026-10-13. Text has been organized for reading; this import has not been independently reviewed by a clinician. It is not individualized medical advice.
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