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Ankylosing Spondylitis
About Ankylosing Spondylitis

Ankylosing Spondylitis

Ankylosing spondylitis (AS) is a form of spinal arthritis—a long-term condition in which the spine and other areas of the body become inflamed.1 There are two types of spinal arthritis, of which only AS can be seen on an X-ray.2 

The complex name ‘ankylosing spondylitis’ holds an explanation of the condition; ‘ankylosing’ meaning stiffness, ‘spondylo’ meaning spine, and ‘-itis’ meaning inflammation.3 You may have noticed that AS has affected other areas of your body; this is because the inflammation can reach beyond the spine, particularly to other joints.2

Outline of a body with arrows pointing to joints in the body: “shoulder joints (connect your shoulder blade to your arm)”, “spinal joints (the joints between your vertebrae)”, “knee joints (connect thigh, shin bone, and knee cap)”, “ankle joints (the joint between lower leg and foot)”, “wrist joints (the joints between forearm and hand)”, “sacroiliac joints (connect your tail bone to your pelvis

AS affects people long-term, developing slowly over several years from its initial appearance, usually during the teenage years or young adulthood. 

The estimated prevalence of AS in the United States is 0.9 to 1.4% of the adult population, similar to that of rheumatoid arthritis .1 However, AS is widely underdiagnosed and likely to affect many more of us than we know.4

References

  1. Ankylosing Spondylitis and Axial Spondyloarthritis. Joel D. Tauroget al., N Engl J Med 2016;374:2563-74. DOI: 10.1056/NEJMra1406182.
  2. Ankylosing Spondylitis Overview– Creaky Joints. Available at: https://creakyjoints.org/about-arthritis/axial-spondyloarthritis/axspa-overview/ankylosing-spondylitis-facts/. Last accessed April 2025.
  3. Merriam-Webster. Medical Dictionary. Available at: https://www.merriam-webster.com/medical. Last accessed April 2025.
  4. Axial spondyloarthritis (including ankylosing spondylitis): How common is it?– NICE CKS. Available at: https://cks.nice.org.uk/topics/axial-spondyloarthritis-including-ankylosing-spondylitis/background-information/prevalence/. Last accessed April 2025.