Ankylosing spondylitis

Ankylosing spondylitis, also called AS, is a form of inflammatory arthritis that affects the spine and joints where your spine meets your pelvis.

Symptoms usually start in the lower spine and progress slowly. In severe cases, the affected spinal joints may become fused and inflexible. This may result in deformity or curving of the spine. 

• Chronic back pain, often felt in your buttocks too, and stiffness that is worse in the morning. The pain often gets better with activity or a warm shower. 
• Inflammation, pain and stiffness in other parts of your body: shoulders, hips, heels, hands and ankles.  
• If your ribs become affected, it will be harder to take a deep breath. You might feel breathless. 
• Some people also get swelling and redness of their eyes. 

Diagnosis is based on your medical history. Your doctor might order a blood test and check your spine’s range of motion. X-rays and MRIs can check for any changes to your bones. You can be tested for a specific gene involved in ankylosing spondylitis.

• Early diagnosis and good management can slow the progression of ankylosing spondylitis, control inflammation, and reduce spinal damage. Medications can relieve pain and stiffness, and lifestyle choices are important to help you live well
• Posture: people with ankylosing spondylitis tend to bend forward and stoop. Keeping the spine straight is important to prevent complications. When standing, keep your bodyweight balanced on both feet with shoulders relaxed (back and down). Do not stand still for too long, and keep a tall, relaxed posture even when moving
• A firm mattress may be more comfortable than a soft one
• A thin pillow can reduce curvature of the spine
• Exercise to keep movement of the spine and strengthen back and neck muscles. Swimming is often recommended
• Physiotherapy and occupational therapy can help to keep your muscles strong and spine flexible
• Stretching exercises will help reduce stiffness and increase flexibility
• A podiatrist may suggest aids to keep good posture
• Relax muscles and get rid of tension. This can help decrease pain and improve sleep and energy levels
• Stop smoking: ankylosing spondylitis can reduce the movement of your rib cage when you breathe, which makes smoking and vaping particularly damaging
• Watch your eyes: about 30% of people will get inflammation of the eyes. The eye may feel irritated and painful. You could also have headaches, blurred vision or sensitivity to light. If this happens see an eye specialist as soon as possible. 

The condition can occur at any age but usually develops between 20 and 30 years of age. It affects men almost three times more often than women.  

Causes include genetic factors plus an environmental trigger.  

Doctors might suggest pain relievers such as paracetamol or non-steroidal anti-inflammatory drugs (NSAIDs). NSAIDs include diclofenac, ibuprofen and naproxen. They help relieve pain and stiffness by reducing inflammation. NSAIDs do have side effects and drug interactions. They are not suitable for everyone so check with your doctor or pharmacist. 

A steroid injection might provide you short-term relief and get pain under control during a flare-up. For more severe AS your rheumatologist may suggest biologic medicines. These are known as disease-modifying drugs and can reduce pain and improve function.  

• Ankylosing spodylitis is much more common in men. It usually starts between 20 and 30 years of age. There is a specific gene that increases your chance of developing this type of arthritis.
• Early diagnosis and treatment can reduce the long-term damage to your spine. If your doctor believes you have ankylosing spondylitis they will refer you to a rheumatologist.

Clinically reviewed in 2024.