Health Topic

Ankylosing Spondylitis

Ankylosing spondylitis is a type of arthritis. It causes inflammation between vertebrae and in the joints between spine and pelvis. Learn more.

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Also called: Rheumatoid spondylitis

Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.

About 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.

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.

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.

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).

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.

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

It sits within Bones, Joints and Muscles and Immune System.

The lead U.S. institute for this subject is the National Institute of Arthritis and Musculoskeletal and Skin Diseases.

When to speak to someone. Reading about a topic cannot tell you whether it applies to you. Speak to a doctor or pharmacist if symptoms are severe, sudden, getting worse, or simply not going away — and seek emergency care immediately for chest pain, breathing difficulty, sudden weakness or confusion, or a serious allergic reaction.

Research on Ankylosing Spondylitis

541 studies areregistered for this condition on ClinicalTrials.gov, the U.S. National Library of Medicine's public registry. A selection is below — the links go straight to the registry entry, not to a summary of ours.

What a registered study does and does not mean. Registration means a study exists and has been declared publicly. It says nothing about whether the treatment being tested works, is safe, or is available to you. Many studies find no benefit — that is what research is for. Never seek out an experimental treatment on the strength of a registry entry alone.

Research currently under way

Research already completed

Study data from ClinicalTrials.gov, a service of the U.S. National Library of Medicine. Retrieved 2026-07-30. Registry entries are supplied by study sponsors and investigators; ClinicalTrials.gov does not verify their scientific validity. PocketsInfo is not affiliated with, and not endorsed by, the NLM or the NIH.

Where to read more

Rather than paraphrase, we point you to the primary sources. Every link below is to a government health agency, a national institute or a recognised medical body — grouped by what you are trying to find out.

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Diagnosis and Tests

Treatments and Therapies

Living With

Genetics

Clinical Trials

Medical subject headings

Clinicians and researchers index this subject under Spondylitis, Ankylosing. These are the terms to use when searching medical literature.

This page is built from the MedlinePlus health topic record for Ankylosing Spondylitis, a service of the U.S. National Library of Medicine (NLM), National Institutes of Health. Information is from MedlinePlus.gov. PocketsInfo is not affiliated with, and is not endorsed by, the NLM or the NIH. Retrieved 30 July 2026.