Ankylosing spondylitis (AS) is a long-term (chronic) condition in which the spine and other areas of the body become inflamed.
The symptoms of AS can vary but usually involve:
back pain and stiffness that improves with exercise and isn’t relieved by rest
pain and swelling in other parts of the body, such as the hips, knees and ribs
fatigue (extreme tiredness)
These symptoms tend to develop gradually, usually over several months or years, and may come and go over time.
In some people, the condition gets better with time, but for others it can get slowly worse.
Read more about the symptoms of ankylosing spondylitis
The symptoms of ankylosing spondylitis (AS) can vary from person to person, but usually develop slowly, over several months or years.
AS usually first starts to develop during later teenage years or early adulthood. The symptoms may come and go, and improve or get worse over many years.
The main symptoms of AS are described below, although you may not develop all of these if you have the condition.
Back pain and stiffness
Back pain and stiffness are usually the main symptoms of AS. You may find:
the pain gets better with exercise but doesn’t improve, or gets worse, with rest
the pain and stiffness is worse in the morning and at night – you may wake up regularly during the night because of the pain
you have pain in the area around your buttocks
Arthritis
As well as causing symptoms in your back and spine, AS can also cause inflammation of the joints (arthritis) in other parts of your body, such as your hips and knees. The main symptoms associated with arthritis are:
pain on moving the affected joint
tenderness when the affected joint is examined
swelling and warmth in the affected area
Enthesitis
Enthesitis is painful inflammation where a bone is joined to a tendon (a tough cord of tissue that connects muscles to bones) or a ligament (a band of tissue that connects bones to bones).
Common sites for enthesitis are:
at the top of the shin bone
behind the heel (Achilles tendon)
under the heel
where the ribs join to the breast bone
If your ribs are affected, you may experience chest pain, and you may find it difficult to expand your chest when breathing deeply.
Fatigue
Fatigue is a common symptom of untreated AS. It can make you feel tired and lacking in energy.