Erythrocyte Sedimentation Rate (ESR)

What is Erythrocyte Sedimentation Rate?

Erythrocyte sedimentation rate (ESR) measures how quickly red blood cells settle in a test tube over one hour. During inflammation, proteins in blood cause red blood cells to clump together and fall faster, making ESR a nonspecific marker of inflammation.

Why is it Tested?

Doctors order ESR to detect inflammation, monitor inflammatory conditions like rheumatoid arthritis or polymyalgia rheumatica, assess disease activity, and track treatment response. It’s often ordered alongside CRP for comprehensive inflammation assessment.

Normal Ranges

Reference ranges vary by gender and age:

Men: 0–15 mm/hr
Women: 0–20 mm/hr

ESR naturally increases with age, and values may be higher in pregnancy and certain other conditions.

Reference ranges vary by authority. Track yours across multiple standards with automatic unit conversions in LabsVault.

What do Abnormal Results Mean?

Abnormal results are not a diagnosis. Always discuss your results with a qualified healthcare provider before making any medical decisions.

Low/Normal ESR

Normal levels suggest:

Minimal inflammation
No significant inflammatory disease
Well-controlled inflammatory condition

High ESR

Elevated levels may indicate:

Inflammatory conditions (rheumatoid arthritis, IBD)
Infections
Certain cancers
Kidney disease
Pregnancy
Advanced age

How to Track Over Time

ESR changes more slowly than CRP, making it useful for monitoring chronic inflammatory conditions over weeks to months. Rising trends may indicate disease flares or progression, while declining levels suggest successful treatment or disease remission.

Erythrocyte Sedimentation Rate