Is it necessary to fast before a blood sedimentation rate test?

Blood sedimentation rate (ESR) testing does not require fasting. The ESR test primarily reflects the rate at which red blood cells settle per hour under static conditions. This measurement is related to plasma viscosity, the aggregability of red blood cells, and the characteristics of the red blood cells themselves. This test is not affected by food intake, so it can be performed after meals. However, if comprehensive tests such as liver and kidney function, blood glucose, or lipid profile are also needed, fasting will be required. Additionally, high-fat, fried, and salt-cured foods should be avoided before blood collection to prevent interference with the accuracy of the ESR results. In summary, fasting is not necessary for ESR testing alone, but follow your doctor's instructions if comprehensive examinations are required.