Ankylosing Spondylitis Symptoms: Early Signs, Diagnosis and When to Seek Help
Persistent lower back pain can be caused by a muscle strain or age-related wear and tear. Although rare, in some people, particularly younger adults, it may be the first sign of ankylosing spondylitis (AS)—a long-term inflammatory condition that mainly affects the spine and sacroiliac joints.
Recognising ankylosing spondylitis symptoms early is important because timely diagnosis and treatment can help control inflammation, reduce pain, maintain mobility, and minimise long-term complications.
This guide explains the symptoms of ankylosing spondylitis, how the condition is diagnosed, treatment options available in the UK, and when you should seek medical advice.
What Is Ankylosing Spondylitis?
Ankylosing spondylitis is a chronic inflammatory arthritis that mainly affects the joints of the spine and the sacroiliac joints, where the spine meets the pelvis.
Unlike common mechanical back pain, AS is caused by inflammation within the joints and the points where tendons and ligaments attach to bone (known as entheses).
Over time, persistent inflammation can lead to new bone formation, causing sections of the spine to become less flexible. However, modern treatments have significantly improved outcomes for many people by reducing inflammation and slowing disease progression.
Ankylosing spondylitis belongs to a group of inflammatory conditions known as axial spondyloarthritis.
What Are the Early Symptoms of Ankylosing Spondylitis?
Early symptoms often develop gradually over several months rather than appearing suddenly.
Common early symptoms include:
- Persistent lower back pain lasting longer than three months
- Morning stiffness lasting more than 30 minutes
- Pain that improves with movement or exercise
- Pain that becomes worse after prolonged rest
- Buttock pain, often alternating between sides
- Night pain that may wake you during the second half of the night
- Fatigue or reduced energy levels
One of the key characteristics is inflammatory back pain, which differs from mechanical back pain because activity usually improves symptoms, whereas rest often makes them worse.
Patients experiencing persistent back pain may also find our guide on 5 Causes of Lower Back Pain helpful in understanding the different possible causes.
Common Ankylosing Spondylitis Symptoms
As inflammation progresses, symptoms may become more widespread.
These can include:
Lower Back Pain
Pain usually begins in the lower back or buttocks and develops gradually.
Unlike muscle strain, it often:
Improves with exercise
Worsens with prolonged sitting or lying down
Causes stiffness first thing in the morning
Reduced Flexibility
Inflammation can make bending, twisting, or reaching more difficult.
Patients may notice:
Difficulty touching their toes
Reduced ability to rotate the neck
Stiffness after inactivity
Pain in Other Joints
Although the spine is mainly affected, some people develop pain in:
Hips
Shoulders
Knees
Ankles
Heel Pain
Inflammation where the Achilles tendon or plantar fascia attaches to the heel is common.
This may cause:
Pain when walking
Tenderness at the back of the heel
Discomfort after resting
Chest Pain or Tightness
Inflammation around the joints connecting the ribs to the breastbone may reduce chest expansion.
Some patients notice discomfort when:
Taking deep breaths
Coughing
Twisting the upper body
Fatigue
Many people experience ongoing tiredness that is disproportionate to their daily activities.
Fatigue may result from:
Chronic inflammation
Poor sleep caused by pain
Increased energy demands from the immune system
Symptoms Outside the Spine
Ankylosing spondylitis is a systemic inflammatory condition and may affect other parts of the body.
These include:
Eye Inflammation (Uveitis)
Symptoms include:
Red eye
Eye pain
Sensitivity to light
Blurred vision
Uveitis requires urgent assessment by an eye specialist.
Bowel Symptoms
Some people with ankylosing spondylitis also have inflammatory bowel disease, such as Crohn’s disease or ulcerative colitis.
Symptoms may include:
Persistent diarrhoea
Blood in stools
Abdominal pain
Psoriasis
A small proportion of patients also develop psoriasis, causing red, scaly patches on the skin.
Ankylosing Spondylitis Symptoms in Women
Historically, ankylosing spondylitis was thought to affect men more often than women, but research now shows that women can also develop the condition.
Women may experience:
- More widespread pain
- Neck pain earlier in the disease
- Greater fatigue
- Delayed diagnosis due to less typical symptoms
The underlying disease process and treatment principles remain the same regardless of sex.
What Causes Ankylosing Spondylitis?
The exact cause remains unknown.
Several factors are believed to contribute.
Genetics
Many people with AS carry the HLA-B27 gene, although not everyone with this gene develops the condition.
Immune System Dysfunction
The immune system mistakenly attacks healthy tissues around the spine and joints.
Family History
Having a close relative with axial spondyloarthritis may increase the likelihood of developing the condition.
When Should You Seek Urgent Medical Help?
Most cases are not emergencies.
However, seek urgent medical assessment if you experience:
- Sudden weakness in one or both legs
- Loss of bladder or bowel control
- Numbness around the buttocks or genitals
- Severe pain following significant trauma
- Sudden loss of vision or a painful red eye
These symptoms require immediate medical attention.
How Is Ankylosing Spondylitis Diagnosed?
Diagnosis is based on a combination of symptoms, examination findings, and investigations.
Your clinician may recommend:
Medical History
Including:
Duration of symptoms
Family history
Pattern of pain
Other inflammatory conditions
Physical Examination
Assessment may include:
Spinal movement
Hip mobility
Chest expansion
Joint tenderness
Blood Tests
Blood tests may assess inflammation using:
C-reactive protein (CRP)
Erythrocyte sedimentation rate (ESR)
Some patients may also be tested for HLA-B27.
Imaging
Depending on your symptoms, imaging may include:
X-rays
MRI scans
MRI is particularly useful for identifying early inflammation before changes appear on X-rays.
Treatment Options
Treatment aims to reduce pain, control inflammation, preserve mobility, and improve quality of life.
Exercise and Physiotherapy
Regular exercise forms an important part of treatment.
A physiotherapist may recommend:
Stretching exercises
Posture training
Strengthening exercises
Breathing exercises
Maintaining an active lifestyle is often beneficial. Our article on The Impact of Lifestyle on Spinal Health explores healthy habits that support spinal wellbeing.
Medicines
Treatment may include:
Non-steroidal anti-inflammatory drugs (NSAIDs)
Disease-modifying medicines where appropriate
Biologic therapies for people with active disease not adequately controlled with first-line treatments
Treatment decisions are individual and made by a rheumatology specialist.
Injections
Occasionally, corticosteroid injections may be used for inflammation affecting specific joints or tendon insertions, although they are not the main treatment for spinal disease.
Is Surgery Ever Needed?
Most people with ankylosing spondylitis do not require spinal surgery.
Surgery may occasionally be considered for:
- Severe spinal deformity
- Certain spinal fractures
- Significant nerve compression
- Hip replacement if the hip joint is severely affected
A spinal surgeon will discuss the potential benefits, risks, and alternatives where surgery is appropriate.
Living with Ankylosing Spondylitis
Many people continue to work, exercise, and enjoy everyday activities with appropriate treatment and self-management.
Helpful strategies include:
- Keeping physically active
- Following your prescribed exercise programme
- Avoiding smoking
- Maintaining a healthy weight
- Attending regular follow-up appointments
- Managing flare-ups with guidance from your healthcare team
If you are living with persistent spinal pain, our guide on Living with Chronic Back Pain: Coping Strategies and Support offers practical advice that may also be helpful.
When to Seek Medical Advice
Arrange an appointment with your GP or healthcare professional if you have:
- Lower back pain lasting longer than three months
- Morning stiffness that improves with movement
- Persistent buttock pain
- Symptoms beginning before the age of 45
- Recurrent episodes of eye inflammation
- Ongoing joint pain with unexplained fatigue
Early assessment can help identify inflammatory back pain and ensure appropriate referral to a rheumatology specialist where needed.
Conclusion
Ankylosing spondylitis is a chronic inflammatory condition that primarily affects the spine and sacroiliac joints. While symptoms often begin with persistent lower back pain and morning stiffness, the condition can also affect other joints, the eyes, and, less commonly, the bowel or skin.
Recognising ankylosing spondylitis symptoms early and seeking medical assessment can lead to earlier diagnosis and access to treatments that help control inflammation, maintain mobility, and improve long-term quality of life. If your symptoms persist or are affecting your daily activities, discussing them with a healthcare professional is an important next step.
Mr Prasad Karpe
Specialising in cervical radiculopathy, slipped discs, spinal stenosis, and minimally invasive spinal surgery across the North East of England.
Disclaimer
This article is for informational purposes only and does not replace professional medical advice, diagnosis, or treatment. Work ability and activity recommendations vary depending on the severity of symptoms and the underlying spinal condition.