Erythrocyte Sedimentation Rate (ESR)

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Latest Edit: Iva Lloyd, ND 2021-08-24 (EDT)

See Also Lab Tests

Erythrocyte Sedimentation Rate or ESR refers to the rate at which erythrocytes or red blood cells settle out of anti-coagulated blood in 1 hour. This test is useful for determining the level of tissue destruction, inflammation, and is indicative of an ongoing disease process that should be investigated.[1],[2]


  • This test is based on the alteration of certain blood proteins in inflammatory conditions, causing aggregation of the red blood cells
  • Aggregation causes the cells to become heavier and fall more rapidly when placed in a vertical test tube
  • The faster the sedimentation, the higher the ESR
  • Increased albumin levels in the blood can lead to decreased ESR
  • Since albumin is produced in teh liver, liver dysfunction can cause decreased albumin productions and therefore increase the ESR

Patient Preparation

  • Hold medications that may affect test results, if indicated
  • Factors which can cause increased levels
  • presence of fibrinogen, globulins, and cholesterol, pregnancy after 12 weeks until 4th week postpartum, young children, menstruation, high hemoglobin values.
  • Drugs: dextran, methyldopa (Aldomet), oral contraceptives, penicillamine, procainamide, theophylline, heparin, and vitamin A
  • Falsely decreased levels
  • having blood samples stand for more than 24 hours, high blood sugar, high albumin levels, high phospholipid levels
  • Drugs: steroids, high dose aspirin, cortisone, quinine

Clinical Implications

Ranges: The following are the reference ranges for this lab. However, lab ranges can vary by laboratory and country. [2]

Standard U.S. Units Standard International Units
Conventional Laboratory Range Males: 0-15 mm/hour Females: 0-20 mm/hour Males: 0-15 mm/hour Females: 0-20 mm/hour
Optimal Range Males: <5 mm/hour Females: <10 mm/hour Males: <5 mm/hour Females: <10 mm/hour
Alarm Ranges Males: >45 mm/hour Females: >45 mm/hour Males: >45 mm/hour Females: >45 mm/hour

High levels indicate:

Low levels indicate:

  • Not significant

Associated Tests


  1. Pagana Kathleen D, Pagana Timothy J, (1998) Mosby's Manual of Diagnostic and Laboratory Tests, Mosby, Inc
  2. 2.0 2.1 Weatherby Dicken, Ferguson Scott (2002) Blood Chemistry and CBC Analysis: Clinical Laboratory Testing from a Functional Perspective, Bear Mountain