Ankylosing spondylitis is a painful, progressive inflammatory disease of the spine. It can also affect other joints, tendons and ligaments and other areas, such as the eyes and heart.
The exact cause is unknown. It typically causes morning stiffness in the low back along with a deep aching feeling. Loss of spinal mobility is common. There is no definitive treatment, but a regular exercise programme can maintain flexibility of the spine and other affected joints.
Ankylosing means fusing together (ankylosis). Spondylitis indicates inflammation involving the joints of the spine and is derived from the Greek words describing the building blocks of the spine (spondylos) and "itis" meaning inflammation. The entire fusing of the spine, as implied by the name of the condition, is not the norm. Many people will only have partial fusion, sometimes limited to the pelvic bones.