Ankylosing spondylitis (AS)

Last updated:

Reviewed by:

Dr Rhianna McClymont

, Lead GP at Livi

Medically reviewed

Ankylosing spondylitis is a type of inflammatory arthritis that mainly affects the spine and can cause pain and stiffness in other parts of the body. Read about the symptoms of ankylosing spondylitis and treatment options.

What is ankylosing spondylitis?

Ankylosing spondylitis or AS (also called axial spondyloarthritis) is a condition that causes inflammation in the spine, resulting in extra bone growth that causes severe back pain and stiffness.

It’s slow to develop, often starting in the joint at the very bottom of the spine (sacroiliac joint). Symptoms usually appear gradually over months or years, often starting in the teenage years or early 20s.

As well as back pain, ankylosing spondylitis can cause stiffness in the shoulders, neck, ribs, hips and knees.

Ankylosing spondylitis symptoms

The symptoms of ankylosing spondylitis develop over time and may come and go. Early symptoms are likely to include:

  • Lower back pain – Worse in the morning and easing through the day or with exercise

  • Pain and stiffness increasing over months, sometimes enough to wake you in the night

  • Stiff or painful shoulders and neck

  • Pain in the buttocks

  • Fatigue or extreme tiredness

When AS develops, you might experience pain and tenderness in your hip and knee joints. It can also lead to pain caused by inflammation at the places where tendons and ligaments join to the bones, commonly the shin, heel and ribs. This is called enthesitis and can be very painful.

You may get other symptoms over time, including:

  • Diarrhoea or stomach upset

  • Anxiety and depression

  • Soreness or inflammation in the eyes

Ankylosing spondylitis causes

The exact cause of ankylosing spondylitis is unknown. It’s been linked to a specific gene that some people carry, called HLA-B27.

Parents pass the gene to children, but not everybody with HLA-B27 develops AS. Research shows there may be environmental factors involved, but it’s still unclear what these are.

Ankylosing spondylitis diagnosis

Ankylosing spondylitis symptoms develop over time, so it can be hard to diagnose early on. In the early stages, many people assume they have common backache.

If you’re experiencing back and joint pain and you think you might have AS, speak to a GP. They will ask you about your symptoms and how long you’ve had them, and if you’ve noticed any patterns with how they come and go.

If a GP suspects you have ankylosing spondylitis, they might want to do some blood tests to check for inflammation and see if you have the HLA-B27 gene.

You might then be referred to a specialist called a rheumatologist who’ll be able to do further tests. These may include X-rays, an MRI and ultrasounds, to have a detailed look at your spine and bones.

Damage or fusing of the bones is a strong sign you may have ankylosing spondylitis. But because you can have symptoms for years before this kind of damage, many people are diagnosed if they have:

  • Inflammation of the joints linking your pelvis and spine (sacroiliac joints) called sacroiliitis

  • Ongoing lower back pain that eases with movement or exercise and doesn’t improve with rest for a minimum of three months

  • Stiffness and reduced mobility in the lower back

  • Restricted movement in the chest and ribcage

Ankylosing spondylitis treatment

There’s no cure for AS, but there are various treatment options for relieving the symptoms and delaying its progress.

Physical therapy

Physical therapy is an integral part of AS treatment, providing pain relief and improving your strength and flexibility. This may include:

  • Physiotherapy – Including exercises and massage to help with mobility

  • Exercise – Swimming, yoga, Pilates and t’ai chi can help to ease your symptoms and prevent stiffness


A GP or rheumatologist will work with you to find the right combination and dose of medicines. You may need a variety of medications, and this may change over time.


Painkillers can help you manage your symptoms while you’re waiting to speak to a rheumatologist and might become part of your long-term treatment.

  • Non-Steroid Anti-Inflammatory Drugs (NSAIDs) – These help to ease pain and swelling. Ibuprofen, naproxen, diclofenac and etoricoxib are examples of NSAIDS

  • Paracetamol – An alternative to NSAIDs that can be used if you’re pregnant or breastfeeding

  • Codeine – A stronger painkiller that can cause side effects like nausea and sickness, constipation and drowsiness.

TNF Blockers

When tissues in your body become inflamed, your cells produce a chemical known as TNF.

Anti-TNF medicines help to block the effects of TNF while also reducing swelling. The doctor may give you an Anti-TNF injection and monitor your symptoms closely.


If painkillers and TNF blockers aren’t effective for you, the doctor may offer you Secukinumab. This medicine works by blocking one of the proteins that cause inflammation.


Corticosteroids are powerful anti-inflammatories. When taken as tablets, they can reduce swelling in your joints. They are also available as injections directly into affected joints.

Corticosteroids injections can cause side effects, like infection, a change in skin colour and damage to the surrounding tissue. So the recommended limit is up to three injections per year, with at least three months between each one.

Disease Modifying Anti Rheumatic Drugs (DMARDs)

Often used to treat arthritis, DMARDs can help reduce inflammation and pain in joints other than your spine. The most common DMARD is called Sulfasalazine.


Most people with AS don’t need an operation, but the doctor may recommend surgery if you’ve got severe joint pain or joint damage or if your hip joint needs replacing.

Health conditions linked to ankylosing spondylitis

Ankylosing spondylitis can affect different parts of your body and lead to other conditions that will need support from a GP or specialist, like:

  • Spine issues – Fused bones in the spine can restrict your mobility and flexibility

  • Damaged joints – AS can affect joints in the knees, rib, neck and feet

  • Eye problems – Iritis is when one eye becomes swollen, red and sensitive to light. It can usually be treated with eye drops, but if left untreated, can affect your sight

  • Osteoporosis – Weak, brittle bones are a common symptom of AS

  • Heart health – AS can increase your risk of stroke and heart disease. You can reduce your risk by staying active, eating healthily and keep conditions like high blood pressure and diabetes well managed

Rare complications of ankylosing spondylitis

Although some complications of AS are very rare, it’s essential to be aware of the symptoms and talk to a GP if you develop them.

  • Cauda equina syndrome – This happens when nerves at the base of the spine are compressed, causing pain or numbness at the bottom of your back

  • Amyloidosis – A build-up of a protein (amyloid) in the heart, kidneys and liver, which can cause extreme tiredness, weight loss, breathlessness, swelling, and tingling or numbness in the feet and hands

Last updated:
Reviewed by:
Lead GP at Livi Dr Rhianna McClymont
Dr Rhianna McClymont, Lead GP at Livi