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Ankylosing spondylitis

Ankylosing spondylitis (AS) is a type of arthritis that causes back pain. It mainly affects your lower spine, but it can also affect your ankles, knees, shoulders and eyes.

Ankylosing spondylitis causes inflammation of the joints between the vertebrae, or bones, in your spine. Eventually, this inflammation can cause your vertebrae and sometimes your pelvic bones to fuse (this is when bones start to grow together across a joint). This makes your spine much less flexible, so you have a lot less movement in your spine.

More men than women get AS and it usually starts between the ages of 15 and 35. We do not know why AS happens, but it can run in families. 90% of people with AS carry a gene called HLA-B27. But that doesn't mean everyone with the gene will get AS – a lot of people have this gene and very few get AS.

Symptoms of ankylosing spondylitis

The most common symptoms of AS are pain and stiffness in your back and neck, which can be worse at night or when you wake up. The stiffness tends to improve once you get moving. The pain usually lasts more than three months.

Other joints might also have pain and swelling. There are also links between AS, an inflammatory eye condition called uveitis, and an inflammatory bowel condition called Crohn's disease.

Diagnosing ankylosing spondylitis

Your GP will take a history of your symptoms, examine your joints and arrange blood tests and an X-ray.

They may also refer you to a rheumatologist (a doctor who specialises in joint problems) who may arrange further investigations such as an MRI scan.

Treating ankylosing spondylitis

There is no cure for AS but medication can help to reduce inflammation and manage pain.

Non-steroidal anti-inflammatory drugs (NSAIDs) such a diclofenac, ibuprofen and naproxen can reduce pain and stiffness.

Pain medication such as paracetamol may help with pain.

Biologic medicines (TNF inhibitors) are disease-modifying medicines used for treating severe AS. The biologics that can be used for AS include adalimumab, etanercept and infliximab.

Self-care for ankylosing spondylitis

If you have AS, keeping active and doing exercises to keep your spine mobile and strong are two of the most important things you can do. It's also important to maintain good posture when sitting and standing. Being smoke-free, sleeping well and eating well can all help too.

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Written by HealthInfo clinical advisers. Last reviewed July 2021.

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Page reference: 78697

Review key: HIANK-78697