Causes
- Autoimmune reaction where the immune system attacks joint tissues
- strongly associated with the HLA-B27 genetic marker
Symptoms
- Persistent lower back and hip stiffness (especially early morning)
- pain easing with exercise but worsening with rest
- reduced spinal flexibility
Risk Factors
- HLA-B27 gene positivity
- family history
- younger age onset (17–45 years)
- male sex
