Ankylosing spondylitis 


Ankylosing spondylitis (AS)

Ankylosing spondylitis is a type of arthritis that affects parts of the spine. In this video, an expert describes the long-term effects of the condition, its most common symptoms and the different treatments available.

Media last reviewed: 06/08/2014

Next review due: 06/08/2016

The spine

Your spine extends from your skull to your pelvis. It is made up of 24 individual bones called vertebrae, which are stacked on top of each other.

The vertebrae are separated by soft pads, or discs, that act as shock absorbers. Each vertebra has two sets of joints called facet joints that, with the discs, allow the spine to bend.

The vertebrae are also held together by tough bands called ligaments. Together with the spinal muscles, the ligaments give the back its strength.

At the bottom of the back there are the two sacroiliac joints at either side of the spine. These transmit the weight of the upper body to the pelvis.

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 

When to seek medical advice

You should see your GP if you have persistent symptoms of AS.

If your GP thinks you may have the condition, they should refer you to a rheumatologist (a specialist in conditions affecting muscles and joints) for further tests and any necessary treatment.

Read more about diagnosing ankylosing spondylitis.

What causes ankylosing spondylitis?

In AS, various areas of the spine and other joints become inflamed.

As well as causing pain, stiffness and swelling, this inflammation can damage affected areas of the body over time, and in some cases can lead to some of the individual bones of the spine fusing (joining together). This fusing of the spine is known as ankylosis.

It is not known what causes the condition, but there is thought to be a link with a particular gene known as HLA-B27.

Read more about the causes of ankylosing spondylitis.

Who is affected

AS tends to first develop in teenagers and young adults. Most cases first start in people aged 20-30, with only a minority of cases first affecting adults over 45.

AS is around three times more common in men than in women.

There are around 200,000 people in the UK who have been diagnosed with the condition.

How ankylosing spondylitis is treated

There is no cure for AS and it is not possible to reverse the damage caused by the condition. However, treatment is available to relieve the symptoms and help prevent or delay its progression.

In most cases, treatment will involve a combination of:

  • exercises carried out individually or in groups to reduce pain and stiffness
  • physiotherapy  where physical methods, such as massage and manipulation, are used to improve comfort and spinal flexibility
  • medication to help relieve pain and reduce inflammation – such as painkillers and a type of medicine called anti-TNF medication

Surgery is sometimes needed to repair significantly damaged joints or correct severe bends in the spine, but this is uncommon.

Read more about treating ankylosing spondylitis.


The outlook for AS is highly variable. For some people, the condition improves after an initial period of inflammation, whereas for others the condition can get progressively worse over time.

Around 70-90% of people with AS remain fully independent or minimally disabled in the long term. However, some people eventually become severely disabled due to the bones in their spine fusing in a fixed position and damage to other joints, such as the hips or knees.

With modern treatments, AS doesn't normally affect life expectancy significantly, although the condition is associated with an increased risk of other potentially life-threatening problems.

For example, AS can lead to osteoporosis (weakening of the bones), spinal fractures and cardiovascular disease (a group of conditions affecting the heart and blood vessels).

Read more about the complications of ankylosing spondylitis.

Page last reviewed: 26/06/2014

Next review due: 26/06/2016


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The 6 comments posted are personal views. Any information they give has not been checked and may not be accurate.

DC 4205 said on 31 August 2014

Hi I'm recently diagnosed with as after a long hard struggle . I've been taking tnf blockers (humira) for 3 months but haven't noticed any great change . Can anyone share there experiences with tnf and how noticeable the changes were and how long it took . My heart goes out to all my fellow sufferers .

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Ambiie said on 01 July 2014

I think I am almost safe in saying that my great aunt has the worse case of AS with fixed posture. She also has they eye conditions associated. Her eyes were once photographed for the medical journals. She is now 77 and hasn't complained a day in her life. She is the most fantastic woman possible and I just wanted to say AS isn't the be all and end all at all

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Janella said on 24 February 2014

I had a very bad outbreak in my thirties and ended up in hospital. Unfortunately, I did not have physio and now cannot lay straight and my neck and spine are 5" out of alignment. Shortly afterwards I was hospitalised with uveitis with no long term effects. Arthritic joints now, treated with acuncture for the pain(successful) but no recurrence of A.S. Aged 76, do Pilates and much gardening!

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Dansetteman said on 14 September 2012

Now in my 55th year of A/S complete with hospital stays at GT Ormond St where 1st diagnosed as TB in 1957, til full accurate diagnosis 1976 at Barts, London. The Min in Bath got me sorted where all others failed me and still thankfully under their caring hands. How times have changed in the NHS from being treated like a piece of spare piece of faulty furniture, to real support, care and understanding in a sharing working partnership.
2nd set of hips chugging on ok and finding regular visits to the swimming pool work best to maintain stamina, general fitness and limb movement. It's not been easy but as they say at Bath plan prioritise and pace are the keys, although when we're younger we disregard this a bit. Don't also set yourself up to fail and not setting unrealistic goals not a bad idea too. Motivation is required and a good sense of humour especially as other can't often understand what we are going through at times.

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Gillian Eames said on 13 September 2012

l have lived with Ankylosing Spondylitis for over 30 years now .Along with my medications being cared for at The Royal National Hospital For Rheumatic Diseases in Bath plays a huge part in being able to self manage my condition. The journey from Bromley in Kent to Bath Somerset is worth every mile to be looked after by the expertise team that specialise in Ankylosing Spondylitis .l attend the RNHRD Bath AS residential course and over the years past and present Physiotherapists that run the AS Courses have passed on to me thier expertise in excersises and AS Stretches to help me to STAND TALL and keep my mobility. The consultants past and present have always treated me as a person and listened to me and helped me to overcome problems i face living with Ankylosing Spondylitis. This condition also affects us physcologically and at the RNHRD they have always been concerned about my physcological state aswell as my physical state. l can honestly say that without this hospital over the last 20 years l would not be the person l am oday living with this condition. They have taught me that medications pay a huge part in managing my AS but also excersises play a huge part in managing my pain levels and keeping my mobility as good as l can. l feel that centres of excellance like the RNHRD in Bath should be promotted and people should have the choice to be treated there if they so wish. So many people are refused funding to be refered to such places being told they can be given the same services whre they live . This is untrue as the treatment and care you recieve from Bath is unique. l would like to thank all staff past and present at the RNHRD for making my life better living with Ankylosing Spondylitis .

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whitespeck said on 02 August 2012

From my experience, the (or a) cause of ankylosing spondylitis is the phenomenon known as RSI occurring in the spine of young people. The immune system resolves the inflammation of the ligament by turning it to bone and fusing the spine together. There may be diet and other aspects involved, especially severe stress.

Ankylosing spondyilitis cases are in danger from back stress situations when taking the drugs because they hide the warning symptoms.

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