- C-reactive protein (CRP) – to check for the presence of inflammation
- Erythrocyte sedimentation rate (ESR) – another test for inflammation
- Complete blood count (CBC) – to check for anemia, a complication of the chronic inflammation associated with ankylosing spondylitis, and increased numbers of white blood cells as a marker of inflammation
- HLA-B27 – to determine if someone has this human leukocyte antigen on their cells, which significantly increases the risk of developing ankylosing spondylitis
- X-rays or other imaging tests – to look for changes in the joints and bones, although it may take several years before characteristic degenerative changes are visible
Early diagnosis allows for interventions that may help to prevent or delay complications of the condition.