Erythrocyte Sedimentation Rate (ESR)
Also called: ESR, Sed rate, Erythrocyte sedimentation rate
ESR is a non-specific inflammation marker measured by watching how fast red blood cells settle in a column. Slow but very sensitive to chronic systemic inflammation.
Published: Updated:
Range source: MedlinePlus — ESR, checked Oct 31, 2026
Check your result
Calculated in your browser - the number is not sent anywhere.
Have the whole report? Upload it - we'll explain every value on it
What does Erythrocyte Sedimentation Rate (ESR) measure?
ESR is the rate at which red blood cells sediment in a vertical column of anticoagulated blood over one hour. Acute-phase proteins (especially fibrinogen) make cells clump and fall faster, so ESR rises in many inflammatory states. It's slower to move than CRP — both up and down — which is why the two are often ordered together: CRP for the acute picture, ESR for chronic inflammatory monitoring. Hugely useful in giant-cell arteritis, polymyalgia rheumatica and rheumatologic flare-tracking, where dramatic elevations (>100 mm/hr) are common.
What is the normal Erythrocyte Sedimentation Rate (ESR) range?
- Rises naturally with age and is a little higher in women. A common rule of thumb: upper normal is roughly age/2 in men, and (age+10)/2 in women.
- Adult upper limits (Westergren method): men under 50 less than 15 mm/hr, men over 50 less than 20 mm/hr; women under 50 less than 20 mm/hr, women over 50 less than 30 mm/hr.
- Pregnancy and anaemia raise it independently of disease.
Your lab's printed range is what counts.
What does a high Erythrocyte Sedimentation Rate (ESR) level mean?
- Active infection or inflammation — bacterial > viral; pneumonia, osteomyelitis, abscess.
- Autoimmune disease flare — rheumatoid arthritis, lupus, polymyalgia rheumatica.
- Giant-cell (temporal) arteritis — ESR almost always >50 mm/hr; sight-threatening if missed.
- Malignancy — myeloma, lymphoma, metastatic cancer.
- Chronic kidney disease, end-stage renal failure — ESR rises non-specifically.
- Pregnancy, anaemia, advanced age — physiological elevations.
What does a low Erythrocyte Sedimentation Rate (ESR) level mean?
- Polycythaemia — more red cells slow the fall.
- Sickle cell disease, hereditary spherocytosis — abnormal cell shape resists clumping.
- Congestive heart failure, severe hypofibrinogenaemia — protein patterns lower the rate.
- A low ESR by itself is not clinically actionable.
Symptoms to look out for
- ESR itself causes no symptoms - it is a marker, and any symptoms come from the underlying inflammation.
- A very high ESR with new headache, scalp tenderness or jaw pain in an older adult is a red flag for giant-cell arteritis and needs urgent assessment.
- Otherwise, read ESR alongside how you feel and other markers, not on its own.
Many out-of-range results cause no symptoms at all - this is context, not a diagnosis.
When to discuss with a doctor
ESR >50 mm/hr in an older patient with new headache, scalp tenderness or jaw pain is a same-day rheumatology consultation — suspected giant-cell arteritis. ESR + CRP together that don't return to normal after a treated infection raise the question of a persistent cause. Mediora.AI shows the value in context; ESR alone is not a diagnostic test.