Erythrocyte Sedimentation Rate

The Erythrocyte Sedimentation Rate (ESR), also known as the sed rate or erythrocyte sedimentation reaction, is used to gauge overall inflammatory activity. It supports the diagnostic evaluation and follow-up of infections, autoimmune diseases, malignancies, and plasma cell dyscrasias. ESR is analytically sensitive to inflammatory changes but is not disease-specific. Results are interpreted in context with clinical assessment and complementary tests.

ESR is an indirect measure of inflammation performed on anticoagulated whole blood. Aggregation of red blood cells, promoted by acute-phase reactants and abnormal plasma proteins, accelerates sedimentation and produces higher values. Automated capillary photometry applies a kinetic measurement and demonstrates close agreement with the reference Westergren method. Older approaches such as the Panchenkov method yield similar results within normal ranges but may diverge at elevated ESR levels. Freshly collected specimens provide the most reliable measurements. Interpretation requires awareness of physiologic and hematologic modifiers. The test has reduced diagnostic utility in severe anemia and in disorders with pronounced red cell shape abnormalities. Reference intervals differ by age and sex, and values are typically higher in females.