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Low back pain and stiffness are the hallmarks of ankylosing spondylitis (AS), but they may not be the first or only symptoms of this inflammatory type of spinal arthritis.
At least 2.7 million people in the United States have ankylosing spondylitis and related forms of arthritis (axial spondyloarthritis), based on data collected in the U.S. National Health and Nutrition Examination Survey 2009–2010 and published in the journal
The disease can be severe, causing the spine to fuse into a fixed, hunched position, but it can also be less dramatic. Some people with ankylosing spondylitis experience only intermittent periods of mild back pain throughout their life.