Investigations

Diagnosis is essentially made on the history – especially gross morning stiffness. The patients often complain of having to roll out of bed.

Examination and results of tests are also helpful:

• The Erythrocyte Sedimentation Rate (ESR) is raised in the overwhelming majority of cases. This means that the red blood cells separate out from the blood plasma at a faster rate than normal, and this indicates inflammation in the body. However, other causes of a raised ESR need to be excluded, such as infection.
• Diagnosis can be made without the presence of a raised ESR.
• Raised C-reactive protein (CRP) is also usual.
• In the presence of raised inflammatory markers, rheumatoid arthritis and myeloma have to be excluded.

Amended November 2008