ESR Stands for Erythrocyte Sedimentation Rate
ESR is the abbreviation for Erythrocyte Sedimentation Rate, a laboratory test that measures how quickly red blood cells (erythrocytes) settle to the bottom of a test tube over a specified time period, typically one hour. 1
What the Test Measures
ESR quantifies the rate at which erythrocytes sediment in a vertical tube, with results expressed in millimeters per hour (mm/h). 2, 3
The test serves as a nonspecific marker of systemic inflammation, as elevated fibrinogen and other plasma proteins during inflammatory states cause red blood cells to aggregate and settle more rapidly. 4, 5
Clinical Terminology and Usage
The term appears consistently across major medical guidelines as "erythrocyte sedimentation rate" with the standard abbreviation ESR. 1
Alternative terminology includes "sedimentation rate" or simply "sed rate" in clinical practice, though ESR remains the formal designation. 6
Normal Reference Ranges
Men: ESR values typically considered elevated when exceeding 20 mm/h. 6
Women: ESR values typically considered elevated when exceeding 30 mm/h, as women have higher baseline values than men. 6
Age affects baseline values, with ESR normally increasing with advancing age. 6
Key Clinical Applications
Screening and monitoring inflammatory conditions including giant cell arteritis, polymyalgia rheumatica, and rheumatoid arthritis. 1, 6
Detecting infections such as osteomyelitis, where highly elevated ESR (≥70 mm/h) has 81% sensitivity and 80% specificity for diagnosis in diabetes-related foot infections. 6
Assessing disease activity through composite scores like DAS28-ESR in rheumatoid arthritis management. 6