Ankylosing Spondylitis

Introduction

If you have been diagnosed with ankylosing spondylitis — often shortened to AS — you are probably trying to understand what this condition will mean for your back, your work, your sleep, and the years ahead. Perhaps your symptoms have been brewing for a long time before a name was finally put to them. Perhaps you have just started a new medication and want to know what to expect. Perhaps your doctor has used a newer term, “axial spondyloarthritis,” and you are unsure how it relates.

This guide is written for people who already have a diagnosis or are being investigated for one. It explains what ankylosing spondylitis is, how doctors approach treatment today, what role exercise and lifestyle play, what to watch out for, and how the outlook has changed over the past two decades. The picture is far more hopeful than it was a generation ago. Earlier diagnosis and the arrival of biologic medicines have allowed many people with AS to keep working, exercising, and living without the severe spinal fusion that was once considered almost inevitable.

AS is a lifelong condition, but it is not a fixed sentence. The choices you and your rheumatologist make — about medication, movement, posture, and follow-up — meaningfully shape how the disease unfolds.

What Is Ankylosing Spondylitis?

Ankylosing spondylitis is a chronic inflammatory disease that primarily affects the spine and the sacroiliac joints — the two joints where the base of the spine meets the pelvis. It is a form of inflammatory arthritis, but unlike osteoarthritis (which is mainly wear and tear), AS is driven by the immune system attacking the body’s own tissues.

AS belongs to a broader family of related conditions called spondyloarthritis. Within this family, doctors increasingly use the term axial spondyloarthritis (axSpA) to describe disease that mainly affects the spine and pelvis. Ankylosing spondylitis is the form of axial spondyloarthritis in which clear structural changes are visible on X-rays. A related form, called non-radiographic axial spondyloarthritis, shows inflammation on MRI but not yet on X-rays. The treatment principles are largely the same.

The word “ankylosing” comes from a Greek word meaning “fused.” In severe, long-standing disease, chronic inflammation at the edges of the vertebrae can lead the body to form new bone, and over years this new bone can bridge the spaces between vertebrae — a process called ankylosis or fusion. Modern treatment is aimed in large part at preventing or slowing this process.

How AS Affects the Body

The areas most often involved are:

• The sacroiliac joints, where the spine meets the pelvis
• The lumbar (lower) and thoracic (mid) spine
• The neck, especially in longer-standing disease
• The hips and shoulders
• The rib joints, which can affect chest expansion when you breathe in
• The entheses — the points where tendons and ligaments attach to bone, such as the heel

AS is a systemic condition, meaning it can affect parts of the body beyond the joints. The most common is the eye, where AS can cause a painful inflammation called uveitis or iritis. Less commonly, the disease is associated with inflammatory bowel disease, psoriasis, and, rarely, problems with the heart valves or lungs.

Causes and Risk Factors

The exact cause of ankylosing spondylitis is not fully understood. It is not caused by something you did or did not do. It is not the result of poor posture, heavy lifting, an old back injury, or stress — although these can affect symptoms.

The Genetic Link: HLA-B27

The strongest known risk factor is a gene called HLA-B27. The majority of people with AS carry this gene. However, having HLA-B27 does not mean you will develop the disease — most people who carry the gene never do. This tells us that other factors, probably including additional genes and environmental triggers, are also involved.

If a close relative has AS or another spondyloarthritis condition, your risk is higher than average, but still far from certain.

Other Risk Factors

• Age of onset: Symptoms usually begin in late adolescence or early adulthood, typically before age 40
• Sex: AS has historically been thought of as more common in men, with men more likely to develop visible spinal fusion. Women are now recognised to be affected almost as often, though sometimes with a different pattern of symptoms
• Family history of AS, psoriasis, inflammatory bowel disease, or uveitis

It is worth repeating: AS is not caused by physical activity, posture, or anything within your control before diagnosis. The diagnosis is not your fault.

Signs and Symptoms

If you are already diagnosed, you will recognise many of these. This section is included because most people with AS continue to experience changing symptoms over time, and it helps to be able to tell “typical AS” from something new that should prompt a call to your specialist.

The Classic Pattern: Inflammatory Back Pain

The hallmark of AS is what doctors call inflammatory back pain, which differs from common mechanical back pain in a few telling ways:

• It comes on gradually, often before age 40
• It lasts more than three months
• It is worse with rest — especially in the second half of the night and early morning
• It improves with movement and exercise, not with bed rest
• It is associated with morning stiffness lasting 30 minutes or longer

Pain often starts in the buttocks (from sacroiliac inflammation) and may alternate from one side to the other before settling.

Other Common Symptoms

• Fatigue, which can be significant and is partly driven by inflammation itself
• Pain or stiffness in the neck, mid-back, or chest wall
• Hip or shoulder pain
• Heel pain or pain in other tendon attachment points (enthesitis)
• Swelling of a single finger or toe (dactylitis)
• Eye pain, redness, and sensitivity to light — a possible sign of uveitis, which needs urgent assessment
• Bowel symptoms in those who also have inflammatory bowel disease

Symptoms That Should Prompt Faster Contact with Your Doctor

• A painful, red eye with light sensitivity or blurred vision
• New or worsening numbness, tingling, or weakness in the limbs
• Loss of bladder or bowel control
• Significant new chest pain or breathlessness
• A sudden, severe worsening of stiffness or pain after a fall, even a minor one (the fused spine is more vulnerable to fracture)

Diagnosis

There is no single test that confirms ankylosing spondylitis. The diagnosis is made by a rheumatologist who puts together the story of your symptoms, the physical examination, blood tests, and imaging.

Clinical Assessment

Your rheumatologist will ask in detail about the pattern of your back pain, morning stiffness, what makes symptoms better or worse, family history, and any history of eye inflammation, psoriasis, or bowel disease. They will check the range of movement of your spine, hips, and chest, and look for areas of tenderness around the sacroiliac joints and tendon attachments.

Blood Tests

• HLA-B27: helpful supporting evidence when positive, but neither confirms nor rules out AS on its own
• CRP and ESR: markers of inflammation; sometimes raised in AS but can also be normal even when the disease is active
• Other tests to rule out conditions that can mimic AS

Imaging

• X-ray of the sacroiliac joints and spine: looks for the structural changes characteristic of AS, but these can take years to appear
• MRI of the sacroiliac joints and spine: can detect active inflammation much earlier than X-ray, and is especially useful in younger patients and those with shorter disease duration

Early diagnosis is one of the most important factors in long-term outcome, because it allows treatment to begin before significant structural damage occurs.

Treatment Goals and Overview

Current international guidance from the Assessment of SpondyloArthritis International Society and the European Alliance of Associations for Rheumatology (the ASAS-EULAR recommendations) and from the American College of Rheumatology frames AS treatment around several goals:

1. Reduce inflammation and symptoms
2. Preserve range of motion and physical function
3. Prevent or slow structural damage to the spine and joints
4. Address related conditions such as uveitis, psoriasis, and inflammatory bowel disease
5. Support quality of life, work, and social participation

Treatment is built on two pillars that work together: non-drug treatment (especially regular exercise and physical therapy) and medication. Neither alone is enough for most people. Decisions about which medications to use, and when to step up therapy, are tailored to each person’s pattern of disease, severity, and response.

Medications for Ankylosing Spondylitis

Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)

NSAIDs are the first-line drug treatment for AS in current ASAS-EULAR and ACR guidance. Examples include ibuprofen, naproxen, diclofenac, indomethacin, and celecoxib. They work by reducing inflammation, pain, and stiffness, and many people with AS notice a marked improvement within days of starting them.

NSAIDs are often used at higher anti-inflammatory doses for AS than for ordinary aches and pains, and continuous use over weeks is generally needed to assess response. Your doctor will balance benefit against the known risks of long-term NSAID use, which include stomach ulcers, kidney effects, and cardiovascular risk. A stomach-protecting medicine is often co-prescribed.

Biologic Therapy

Biologics are a class of injectable or intravenous medicines that target specific signals in the immune system responsible for inflammation. They have transformed the outlook for AS over the past two decades.

According to ASAS-EULAR and ACR guidance, biologics are typically considered for patients whose disease remains active despite a proper trial of at least two NSAIDs. The two main classes used in AS are:

• TNF inhibitors — medicines that block tumour necrosis factor, a key inflammatory protein. Examples include adalimumab, etanercept, infliximab, golimumab, and certolizumab pegol
• IL-17 inhibitors — medicines that block interleukin-17, another inflammatory signal. Examples include secukinumab and ixekizumab

Both classes have been shown in clinical trials to reduce pain, stiffness, and inflammation seen on MRI, and to improve function. Choice between them depends on factors such as other conditions (for example, TNF inhibitors are often preferred when uveitis or inflammatory bowel disease is also present), prior response, and individual considerations discussed with your rheumatologist.

A newer class, JAK inhibitors (taken as a tablet), such as upadacitinib and tofacitinib, has more recently been approved for AS and offers an oral alternative for some patients.

Before starting biologic or JAK therapy, screening tests are usually done for tuberculosis, hepatitis B and C, and sometimes other infections, because these medicines reduce parts of the immune response.

Conventional DMARDs

Conventional disease-modifying anti-rheumatic drugs such as sulfasalazine and methotrexate have a limited role in AS. Current guidelines indicate they are not effective for the spinal disease itself, but sulfasalazine may be considered when peripheral joints (such as knees) are the main problem and biologics are not an option.

Corticosteroids

Long-term oral steroids are generally avoided in AS. Local steroid injections into a single inflamed joint or sacroiliac joint can be useful for a localised flare. Steroid eye drops, prescribed by an ophthalmologist, are part of treatment for uveitis flares.

Pain-Relieving and Supporting Medicines

Exercise is not optional in ankylosing spondylitis — it is part of the treatment. Both ASAS-EULAR and ACR guidance describe regular exercise and physical therapy as a cornerstone of management, alongside medication. Studies consistently show that people with AS who exercise regularly have less pain, better mobility, and better function over time than those who do not.

What Helps

• Stretching and range-of-motion exercises for the spine, hips, and shoulders — ideally daily
• Posture training to counter the tendency toward a stooped posture
• Core and back strengthening
• Aerobic exercise such as swimming, walking, or cycling
• Deep breathing exercises to maintain chest expansion
• Group exercise programmes for AS, where available, which combine social support with structured movement

Many people find swimming particularly helpful because the water supports body weight and allows a wider range of movement than land-based exercise.

What to Be Cautious About

High-impact contact sports (such as rugby or martial arts) carry a higher risk of spinal injury, especially when fusion has begun. Discuss specific activities with your rheumatologist or physiotherapist. The general principle is to stay active and consistent rather than to push hard intermittently.

Working with a Physiotherapist

A physiotherapist experienced with AS can build an exercise programme suited to your pattern of disease, current mobility, and preferences. Even a few sessions at the start can teach you techniques you carry on at home for years.

Lifestyle and Self-Management

Posture and Sleep

Spending long periods slumped forward — over a desk, phone, or steering wheel — encourages the stooped posture AS can cause. Frequent breaks to stand, walk, and stretch are valuable. A firm mattress and a thin pillow are often more comfortable than a soft mattress and high pillow, although this varies. Sleeping flat on the back, with legs straight, helps maintain alignment for some people.

Smoking

Smoking has been linked in studies to worse pain, faster structural progression, and reduced response to biologic treatment in AS. Stopping smoking is one of the most impactful self-management steps a person with AS can take.

Weight and Diet

There is no specific diet that treats AS. A balanced, anti-inflammatory style of eating — with plenty of vegetables, fruits, whole grains, fish, and healthy fats — supports general health, helps keep weight in a healthy range, and may help with cardiovascular risk, which is somewhat elevated in inflammatory arthritis. Crash diets and unproven elimination diets are not supported by current evidence.

Bone Health

AS is associated with an increased risk of osteoporosis, even in younger people. Adequate calcium and vitamin D intake, weight-bearing exercise, and avoiding smoking and excess alcohol all support bone health. Your rheumatologist may arrange a bone density scan at some point and consider treatment if needed.

Emotional Well-Being

Living with a chronic condition that affects pain, sleep, and energy can take a toll on mood. Anxiety about long-term mobility is common, particularly soon after diagnosis. Speaking with your doctor, a psychologist, or a peer support group can ease this. Effective treatment of inflammation itself often improves mood, energy, and sleep substantially.

Monitoring and Follow-Up

Ankylosing spondylitis is a long-term condition, and monitoring is essential to keep it controlled and to adjust treatment as needed.

A typical follow-up plan includes:

• Review with a rheumatologist every three to six months, more often when treatment is changing or disease is active
• Disease activity assessments — commonly using scoring tools such as BASDAI (a questionnaire) and ASDAS (which combines symptoms with a blood inflammation marker)
• Blood tests for inflammation (CRP) and to monitor medication safety
• Occasional imaging if disease progression is suspected
• Periodic checks of blood pressure, cholesterol, and cardiovascular risk
• Eye review if there has been uveitis
• Bone density assessment over time

Keeping a simple symptom and flare diary — noting pain, stiffness, sleep, and what helps — can make follow-up appointments more productive.

Flares: What They Are and How to Manage Them

A flare is a temporary worsening of inflammation. After a period of feeling well, you may notice:

• Increased pain in the back, hips, or other joints
• Longer morning stiffness
• Greater fatigue
• New eye redness or bowel symptoms

Some flares settle within days to a couple of weeks. Others signal that the current treatment is no longer enough.

What helps in a flare:

• Keeping up gentle movement and stretching, even if reduced in intensity — bed rest tends to worsen stiffness
• Using heat (warm shower, heat pack) or cold packs, whichever helps you most
• Adjusting NSAID use within the dose your doctor has agreed
• Contacting your rheumatologist if a flare is severe or lasts more than a couple of weeks, or if there is a red eye, fever, or other concerning symptom

Tracking patterns can help — some people identify triggers such as poor sleep, illness, stress, or stopping exercise.

Complications

With current treatment, severe complications are less common than they once were, but it is helpful to know what is being prevented and monitored.

Spinal Complications

• Spinal fusion (ankylosis): over years, the vertebrae can become bridged by new bone, reducing flexibility
• Postural changes: a forward-stooped posture (kyphosis), particularly when the upper back is affected
• Spinal fractures: a fused spine is more brittle and can fracture from even minor injury; new or sudden severe pain after a fall warrants urgent assessment

Hip Involvement

The hip joints can be affected. Severe hip disease may eventually require hip replacement surgery, which generally has good outcomes in AS.

Eye: Uveitis

Around one in three people with AS will experience uveitis at some point. Symptoms include a painful red eye, blurred vision, and light sensitivity. It needs urgent assessment by an ophthalmologist — treatment is straightforward but delay can cause lasting damage.

Heart and Lungs

Inflammation of the heart valves or the electrical conduction system can occur but is uncommon. People with AS have a modestly increased risk of cardiovascular disease overall, which is one reason monitoring blood pressure, cholesterol, and lifestyle factors matters. Restricted chest wall movement and, rarely, scarring at the top of the lungs can affect breathing.

Osteoporosis

Bone thinning can develop earlier and more often than in the general population, sometimes in younger people, and contributes to fracture risk.

Related Conditions

Inflammatory bowel disease (Crohn’s disease, ulcerative colitis) and psoriasis are more common in people with AS than in the general population and may require their own treatment.

Living with Ankylosing Spondylitis

A diagnosis of AS does not mean losing independence, work, or the activities you enjoy. With current treatment, most people maintain function and continue careers, relationships, hobbies, and travel. The condition becomes a part of life rather than the centre of it.

Work

Many people with AS work full-time. Jobs that allow movement, position changes, and short breaks tend to be easier than those requiring long static postures. Reasonable adjustments — a supportive chair, the ability to stand and stretch, flexible hours during flares — can make a substantial difference. Heavier manual roles may need more thought.

Driving and Travel

Long periods sitting in one position can cause stiffness. Frequent breaks, neck rotation exercises, and supportive seating help. For long flights, aisle seats and walking when possible are useful. Wing or rear-view mirror adjustments are important if neck movement is restricted.

Pregnancy and Family Planning

Most people with AS can have healthy pregnancies. Some experience improvement in symptoms during pregnancy and others a flare, particularly after delivery. Several AS medications need to be reviewed before conception — some NSAIDs and some biologics have specific considerations during pregnancy and breastfeeding. A pre-pregnancy discussion with your rheumatologist is valuable so that treatment can be planned safely for both parent and baby.

Sleep

Pain and stiffness at night are common in active AS and disrupt sleep. Better disease control usually improves sleep. Practical steps — a regular bedtime, a warm shower before bed, gentle stretching, and a supportive mattress — can also help.

Relationships and Sexual Health

Pain, stiffness, fatigue, and the emotional impact of a chronic condition can all affect intimate relationships. Open communication with a partner, and with your doctor if needed, helps. Physical adjustments — timing, positions, pacing — can ease physical discomfort.

Ankylosing Spondylitis in Children and Adolescents

AS occasionally begins in childhood or adolescence, where it is part of a broader group of conditions called juvenile spondyloarthritis or, sometimes, enthesitis-related arthritis. The pattern in young people can differ from adult AS:

• Symptoms often start in the hips, knees, or heels rather than the lower back
• Inflammation of tendon attachment points (enthesitis) is common, especially at the heel
• Sacroiliac and spinal symptoms may develop later
• Eye involvement (uveitis) can occur

Diagnosis and care are led by a paediatric rheumatologist. Treatment principles are similar to those for adults — NSAIDs, physiotherapy, and biologics when needed — but with attention to growth, bone development, school participation, and the emotional aspects of having a chronic condition during adolescence. Schools can often make small adjustments — movement breaks, supportive seating, accommodations during flares — that make a meaningful difference.

For most young people with juvenile spondyloarthritis, early specialist care allows continued normal participation in school, sport, and friendships.

Long-Term Outlook

The outlook for people diagnosed with ankylosing spondylitis today is substantially better than it was a generation ago. Earlier MRI-based diagnosis, the routine use of structured exercise, and the availability of TNF and IL-17 inhibitors have changed what the disease typically looks like over decades. Severe spinal fusion is no longer an expected outcome for most patients.

Several factors are associated with better long-term outcomes:

• Earlier diagnosis and treatment
• Consistent exercise and physiotherapy
• Not smoking
• Adherence to medication and regular follow-up
• Good control of inflammation, as measured by symptoms and inflammatory markers

AS remains a lifelong condition. Some people experience long periods of low disease activity or near-remission; others have more persistent symptoms. The aim of modern care is not necessarily complete cure, but sustained low disease activity, preserved function, and a full life alongside the condition.

When to Seek Urgent Care

Contact your rheumatologist or seek urgent medical attention if you experience any of the following:

• A painful, red eye, especially with blurred vision or light sensitivity
• Sudden, severe new back or neck pain, particularly after a fall, even a minor one
• New numbness, weakness, or tingling in the arms or legs
• Loss of bladder or bowel control
• Significant chest pain or breathlessness
• Signs of infection — fever, chills, persistent cough — especially if you are taking a biologic, JAK inhibitor, or other immune-modulating medicine

Frequently Asked Questions

Is ankylosing spondylitis curable?

There is no cure for AS at present, but it is highly treatable. With current medication and exercise, many people achieve low disease activity or near-remission, with minimal day-to-day symptoms and preserved function.

Will I end up with a fused spine?

Severe spinal fusion is much less common than it used to be. Earlier diagnosis and modern treatments have shifted the typical course of the disease. Most people diagnosed today, who engage with treatment and exercise, retain meaningful spinal flexibility long-term.

Do I need to take medication for the rest of my life?

Many people need ongoing treatment to keep inflammation controlled. The intensity may change over time — some people are able to reduce doses or spacing of biologic injections during stable periods, under their rheumatologist’s guidance. Stopping treatment entirely often leads to a flare, so changes are made carefully.

Is it safe to exercise if I am in pain?

For most people with AS, gentle, regular movement during pain actually helps more than rest. The exception is sudden severe new pain, particularly after an injury, where you should be assessed first. A physiotherapist familiar with AS can help you find activities suited to your current state.

Can I still have children?

Yes. AS does not reduce fertility in most people. Some medications need to be reviewed before pregnancy, so a planned conversation with your rheumatologist before trying to conceive is helpful.

What is the difference between ankylosing spondylitis and axial spondyloarthritis?

Axial spondyloarthritis is the broader umbrella term. Ankylosing spondylitis is the form in which X-ray changes are clearly visible. Non-radiographic axial spondyloarthritis is the form with inflammation visible on MRI but not yet on X-ray. The treatment approach is largely the same.

Does AS affect women differently?

AS occurs in women more often than was once recognised. Women may have somewhat different symptom patterns — for example, more neck and peripheral joint involvement — and may be diagnosed later, in part because the condition has historically been thought of as a male disease. Treatment principles are the same for all patients.

Are biologics safe long-term?

Biologics have now been used for AS for over two decades, and the long-term safety data are reassuring. The main risk is infection, because these medicines reduce part of the immune response. Screening before starting and regular monitoring on treatment are designed to manage this risk. Your rheumatologist will discuss specific considerations for the medicine being chosen.

Will my children inherit AS?

There is an increased risk in close relatives of people with AS, partly through the HLA-B27 gene, but most children of people with AS will not develop it. There is no current need for routine genetic testing of family members in the absence of symptoms.

Conclusion

Ankylosing spondylitis is a chronic inflammatory condition, but it is one that medicine has come to understand and treat much better over the past twenty years. Earlier diagnosis with MRI, the central role of regular exercise and physiotherapy, and the arrival of TNF inhibitors, IL-17 inhibitors, and newer oral therapies have together changed the typical outlook from one of inevitable spinal fusion to one in which most people can expect to maintain mobility, function, and a full life.

The condition does ask for a partnership — with a rheumatologist, with a physiotherapist, and with yourself. Consistent movement, attention to posture, not smoking, sleeping well, and keeping up with medication and follow-up are the elements that quietly add up over years.

If your diagnosis is new, the early period can feel overwhelming. Most people find that as treatment takes effect and a routine settles, life finds its rhythm again. The condition becomes one part of who you are, not all of it.