Inflammation
Erythrocyte sedimentation rateESR
Indirect inflammation marker; useful in temporal arteritis, polymyalgia rheumatica, and osteomyelitis.
Sample
EDTA whole blood, run within 4 h
Clinical reference range
— to 15 mm/h
Westergren male
Conv: —–15 mm/h
Biology
What it measures
Rate of RBC sedimentation in 1 hour, accelerated by fibrinogen-mediated rouleaux formation.
Clinical use
Why we order it
Diagnose and monitor giant cell arteritis (typically >50), PMR, osteomyelitis, abscess.
Differential
Causes of abnormal values
Causes of HIGH
- ↑Inflammation/infection
- ↑Multiple myeloma (very high)
- ↑Pregnancy
- ↑Anemia
- ↑Older age (Westergren rule: men age/2; women (age+10)/2)
Causes of LOW
- ↓Polycythemia
- ↓Sickle cell
- ↓Microcytosis
- ↓Cryoglobulinemia
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