Erythrocyte Sedimentation Rate (ESR)

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.

• 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.
• Typical adult upper limits are around 15-20 mm/hr (younger men) up to 30-40 mm/hr (older women).
• Pregnancy and anaemia raise it independently of disease.

Your lab's printed range is what counts.

• 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.

• 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.

• 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.