Ankylosing spondylitis

Published by Bupa’s Health Information Team, October 2011.

This factsheet is for people with ankylosing spondylitis, or who would like information about it.

Ankylosing spondylitis is a type of arthritis that mainly affects the joints in the spine. It causes stiffness and reduced movement, and some of the bones of the spine may eventually fuse together.

About ankylosing spondylitis

Ankylosing means fusing together and spondylitis means inflammation of the bones in your spine. If you have ankylosing spondylitis, the bones in your spine become inflamed at the part where they attach to the tendons, and also at the joints between the bones. Your body then tries to mend the damage by producing new bone. As new bone grows, it can eventually cause your spine to fuse together.

Although it usually starts in the spine, ankylosing spondylitis can affect any of your joints, especially your hips, knees and shoulders.

You can develop ankylosing spondylitis at any time, but it usually starts in late adolescence and early twenties. Men are three times more likely to be affected than women.

Image illustrating how ankylosing spondylitis can affect the spine

Symptoms of ankylosing spondylitis

Ankylosing spondylitis affects different people in different ways. Symptoms often develop gradually – they may be mild or severe, and can come and go. They may include:

  • persistent back pain and stiffness for more than three months – this is worse in the morning and improves as you move around or exercise
  • pain and swelling of your hip, knee or other joints
  • aching in your chest or ribs, making it difficult for you to breathe
  • bowel problems, known as inflammatory bowel disease
  • recurrent inflammation of tendons or ligaments, such as Achilles tendonitis or plantar fasciitis

If you have any of these symptoms, see your GP.

Complications of ankylosing spondylitis

You may get inflammation of your eye, known as iritis. Your eye may become red, painful and sensitive to light. This needs to be treated quickly as it can cause damage to your eye, and, rarely, blindness. If your eye becomes bloodshot and painful, see your GP straight away.

If you have ankylosing spondylitis, osteoporosis can develop in your spine. Osteoporosis is a condition that causes your bones to become weak and brittle, increasing the risk of fracture.

Some people with ankylosing spondylitis develop problems with their heart and lungs, such as heart disease or scarring of the lungs (fibrosis). These problems are very rare.

Causes of ankylosing spondylitis

It’s not fully understood what causes ankylosing spondylitis, but it can run in families. If you have a gene called HLA-B27, you may be more likely to develop the condition. Research has shown that nine in 10 people who have ankylosing spondylitis have this gene. A simple blood test can check if you have this gene, but having it doesn’t mean you will definitely get ankylosing spondylitis.

Diagnosis of ankylosing spondylitis

You may have symptoms for many years before you’re diagnosed with ankylosing spondylitis because early symptoms are similar to back pain.

Your GP will ask about your symptoms and examine you. He or she may also ask you about your medical history. Your GP may suspect you have the condition after listening to you describe your symptoms and doing a physical examination.

If your GP thinks you may have ankylosing spondylitis, he or she will refer you to a rheumatologist – a doctor who specialises in diagnosing and treating conditions that affect the musculoskeletal system. You may have blood tests, and an X-ray or MRI scan of your hip or spine.

Treatment of ankylosing spondylitis


Exercising may provide relief from the pain and help to improve and maintain your posture, flexibility and mobility. It’s especially important to exercise your back so that it doesn’t stiffen in a bent position. A physiotherapist (a health professional who specialises in maintaining and improving movement and mobility) can give you exercises to do to help you maintain as much movement as possible. These may involve breathing exercises to keep your ribs and chest flexible, and others that target your back, neck, arms and legs. Doing physiotherapy in a pool (known as hydrotherapy) or swimming regularly can be particularly useful as it can help to strengthen your muscles without putting weight through your joints.

There is little evidence to suggest that removing certain types of food from your diet will help. However, it’s important to eat a healthy, balanced diet to maintain a healthy weight. If you’re overweight, this may increase the strain on your back and other joints, and may make your pain worse.

You may find that a hot shower or bath helps with stiffness in the morning, and using hot water bottles, or electric blankets can ease your pain. However, take care not to hold hot items directly against your skin as it may damage your skin. You may also find it helpful to sleep on a firm mattress for support to stop your back from curving.


Painkillers and anti-inflammatory medicines

Your GP or rheumatologist will usually advise you to try non-steroidal anti-inflammatory drugs (NSAIDs) first, to help with your pain. NSAIDs will reduce inflammation and pain so that you can keep active. You can buy some NSAIDs, such as ibuprofen (eg Nurofen), from your pharmacist. Other NSAIDs, such as naproxen, have to be prescribed by your GP.

These medicines can have side-effects such as stomach pain or bleeding from the stomach. Talk to your GP or pharmacist if you need to take NSAIDs regularly, and see your GP immediately if you experience any pain that feels like indigestion while taking NSAIDs.

If you can’t take NSAIDs for any reason, your doctor may advise you to take another painkiller, such as paracetamol, instead. Or he or she may prescribe a medicine called a proton pump inhibitor to take at the same time as an NSAID, to help reduce the side-effects on your stomach.

Always read the patient information leaflet that comes with your medicine and if you have any questions, ask your pharmacist for advice.

Your doctor can also prescribe steroid joint injections, which he or she injects into joints (such as your knee) if they are very painful or swollen.

Disease-modifying anti-rheumatic drugs (DMARDs)

Depending on how severe your disease is, your rheumatologist may also prescribe disease-modifying anti-rheumatic drugs, such as methotrexate or sulfasalazine. These medicines are used for other types of arthritis that are caused by inflammation (for example, rheumatoid arthritis). They work by changing the actual disease process of ankylosing spondylitis and may help reduce the damage to your joints. It may take some time before you notice any effect.

Tumour necrosis factor (TNF) blockers

If you have severe ankylosing spondylitis and NSAIDs or disease-modifying anti-rheumatic drugs don’t help relieve your symptoms, your rheumatologist may recommend a type of medicine called a tumour necrosis factor (TNF) blocker. TNF is a chemical that is made by your cells when you get inflammation. TNF blockers (for example, etanercept and adalimumab) are given by injection that reduces inflammation. These are a newer type of treatment for ankylosing spondylitis and their long-term effects aren’t well known. However, many millions of people with inflammatory diseases have now been treated with these agents worldwide. Speak to your rheumatologist about the risks and benefits of taking TNF blockers.


Biphosphonates (for example, pamidronate) affect bone metabolism and are used to prevent or treat osteoporosis (where bones lose density). However, they are also sometimes used in the treatment of ankylosing spondylitis. Your rheumatologist may prescribe these if he or she thinks these medicines will help you.


Most people with ankylosing spondylitis don’t need surgery, but if your hip or knee is severely affected, your doctor may recommend replacing the damaged joint. In exceptional circumstances, you may need to have surgery on your spine or neck to correct a severe stoop.

Living with ankylosing spondylitis

You will probably be able to carry on with your daily life and work as usual. However, you may need to make some adjustments to your working environment and need special equipment to enable you to do your job more easily. Talk to your occupational health or HR manager for advice, or contact the Citizens Advice Bureau. 

For answers to frequently asked questions on this topic, see FAQs.

For sources and links to further information, see Resources.

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  • This information was published by Bupa's Health Information Team and is based on reputable sources of medical evidence. It has been reviewed by appropriate medical or clinical professionals. Photos are only for illustrative purposes and do not reflect every presentation of a condition. The content is intended only for general information and does not replace the need for personal advice from a qualified health professional. For more details on how we produce our content and its sources, visit the about our health information page.

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  • Publication date: October 2011