What are the symptoms of ankylosing spondylitis (AS)?
In the early stages, ankylosing spondylitis and the related conditions are likely to cause:
- stiffness and pain in the lower back in the early morning which eases through the day or with exercise
- pain in the sacroiliac joints (the joints where the base of your spine meets your pelvis), in the buttocks or the backs of your thighs.
Some people first notice problems after a muscle strain, so the condition is often mistaken for common backache. However, stiffness that lasts at least 30 minutes in the morning helps to distinguish ankylosing spondylitis from simple back pain. The symptoms may also occur after rest, or may wake you in the night.
You may also have neck, shoulder, hip or thigh pain, which is often worse if you've been inactive for a time, for example if you work at a computer. Some people have pain, stiffness and swelling in their knees or ankles. In psoriatic arthritis, the smaller joints of the hands and feet may be affected. For some people, especially children and teenagers, the first signs may be in their hip or knee rather than their back.
Inflammation can occur anywhere in the body where tendons attach to bone (this is called enthesitis), for example, at the elbow and heel. Inflammation comes and goes so the symptoms may vary over time.
The inflammation that causes these symptoms comes and goes, so the degree of pain can vary over time and from person to person. If the condition is mild and only affects the sacroiliac joints, it may go almost unnoticed, but if most of the spine is affected it can cause difficulty with activities that involve bending, twisting or turning.
Other possible symptoms include:
- tenderness at the heel – This makes it uncomfortable to stand on a hard floor. Inflammation can occur at the back of your heel where the Achilles tendon meets the heel bone, or in the tendon in the arch of the foot which is known as plantar fasciitis.
- pain and swelling in a finger or toe – When the whole digit is swollen it’s known as dactylitis.
- tenderness at the base of your pelvis (ischium) – This makes sitting uncomfortable.
- chest pain or a ‘strapped-in’ feeling that comes on gradually – If your spine is affected at chest level (the thoracic spine) it can affect movement at the joints between the ribs and the breastbone, which makes it difficult for you to take a deep breath. Your ribs may be very tender, and you may feel short of breath after even gentle activity. Coughing or sneezing may cause discomfort or pain.
- inflammation of the eye (uveitis or iritis) – The first signs of this are usually a red (bloodshot), watery and painful eye, and it may become uncomfortable to look at bright lights. If this happens, or if you develop blurred vision, it's important to get medical help within 24–48 hours. The best place to go is an eye casualty department – this might not be at your local hospital. Your GP surgery, local A+E or your optician will know where the nearest eye casualty department is. Treatment is usually with steroid eye drops, which are generally very effective. Some people get repeated attacks of eye inflammation, but they're extremely unlikely to cause permanent damage if they're treated promptly.
- inflammation of the bowel – People with ankylosing spondylitis can develop bowel problems known as inflammatory bowel disease (IBD) or colitis. Tell your doctor if you have diarrhoea for more than 2 weeks or begin to pass bloody or slimy stools. You might be referred to a bowel specialist (gastroenterologist). Symptoms of IBD can vary, but it can usually be treated successfully with medication. Sometimes treatments like non-steroidal anti-inflammatory drugs (NSAIDs) can make bowel problems worse, so you might be advised to stop taking them.
- tiredness (fatigue) – This may be caused by the activity of the condition, anaemia or sometimes depression and frustration associated with the condition.