About AS
Ankylosing Spondylitis Defined
Spondylitis (spon-dill-EYE-tiss):
An inflammation of the vertebrae.
Ankylosing (ank-kih-low-sing):
Fusing of the joints.
Ankylosing spondylitis facts
Ankylosing spondylitis (AS) is a form of arthritis. It primarily affects the joints of the spine, although other joints may be
involved as well.1 According to the
Spondylitis Association of America, there are at least half a million
people with ankylosing spondylitis in the U.S.2 AS causes inflammation, pain, stiffness, and — in advanced cases —
can cause disability and deformity, including a permanent fusing of the spine in a stooped-forward position.1
While the severity of ankylosing spondylitis can vary widely from one patient to another, almost all patients will experience
episodes of acute pain — known as "flares" — followed by periods when the symptoms temporarily subside.
How do you know it's ankylosing spondylitis?
The telltale feature of ankylosing spondylitis is an inflammation of the sacroiliac (SI) joints at the base of the spine. SI involvement
is difficult to detect with x-rays until the disease is quite advanced, which accounts for much of the difficulty in diagnosis.3
Recent studies, however, have shown that the use of MRI (magnetic resonance imaging) holds promise for diagnosing AS in its early stages.
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