What causes it?

The exact cause isn’t fully understood. It likely results from a combination of:

• Genetics (many people with AS carry the HLA-B27 gene, though not everyone with this gene develops the disease).
• Immune system dysfunction.
• Environmental factors.

How is it diagnosed?

There is no single test for AS. Diagnosis is based on:

• Your symptoms and medical history.
• Physical examination.
• Imaging such as X-rays or MRI of the sacroiliac joints and spine.
• Blood tests, including markers of inflammation and sometimes HLA-B27 testing.

Ankylosing spondylitis (AS) is a chronic inflammatory disease that mainly affects the spine and the joints where the spine connects to the pelvis (the sacroiliac joints). Over time, ongoing inflammation can lead to pain, stiffness, and, in some people, new bone formation that reduces spinal flexibility.

Common symptoms

Symptoms usually begin before age 45 and often develop gradually. They can include:

• Persistent low back pain and stiffness lasting more than 3 months.
• Pain that is worse after rest (such as in the morning or after sitting) and improves with movement or exercise.
• Pain in the buttocks, sometimes alternating from one side to the other.
• Reduced flexibility of the back or neck.
• Fatigue.
• Pain where tendons and ligaments attach to bone (called enthesitis), such as at the heels.

Living with Ankylosing spondylitis can affect mental health in several ways. Research consistently shows that people with AS have higher rates of anxiety and depression than the general population, although not everyone with AS experiences these challenges.

Some of the reasons include:

• Chronic pain: Ongoing pain can increase stress, irritability, and emotional exhaustion.
• Fatigue: Persistent fatigue can make it harder to work, socialize, or enjoy activities, contributing to low mood.
• Sleep disruption: Pain and stiffness often interfere with sleep, which can worsen anxiety and depression.
• Reduced mobility: Difficulty with movement or physical limitations may lead to frustration or loss of independence.
• Uncertainty about the future: Concerns about disease progression, work, or relationships can increase emotional distress.
• Inflammation: Some evidence suggests that inflammation itself may contribute to changes in mood, although this relationship is still being studied.