Erythrocyte Sedimentation Rate (ESR) Test Procedure

Erythrocyte Sedimentation Rate (ESR) Test Procedure

The erythrocyte sedimentation rate (ESR) is a medical laboratory measurement of the rate at which red blood cells settle from whole blood. This test can help diagnose and monitor various conditions such as inflammation, infection, cancer, rheumatic diseases, and other autoimmune disorders. The ESR test procedure involves several steps, including pre-test procedures, blood collection, clotting, and reading the results.

Pre-Test Procedures

Before the ESR test, patients should inform their healthcare provider of any medications they are taking, especially aspirin, heparin, corticosteroids, or anticoagulants, as these can affect the ESR test results.

Blood Collection

A blood sample is typically collected from the patient's arm, using a sterile needle to withdraw a small amount of blood. The blood sample is then transferred to a test tube or vial, which is sealed and labeled for processing.

Clotting

The blood in the test tube or vial is allowed to clot for at least 15 minutes. During this time, the red blood cells begin to settle due to gravity, forming a bed on which other cells and particles can settle.

Reading the Results

After the clotting process is complete, the tube or vial is carefully inverted to mix the blood and release any remaining red blood cells. The ESR is then measured by reading the height of the sediment layer formed by the red blood cells.

The ESR test results are usually reported in millimeters per hour (mm/h) or millimeters per hour at 37°C (mm/h at 37°C). Normal values for ESR can vary slightly between laboratories, but in general, a result of less than 20 mm/h is considered normal.

In summary, the ESR test procedure involves pre-test procedures, blood collection, clotting, and reading the results. It can be affected by various factors, including medication use, and is used to diagnose and monitor conditions associated with inflammation, infection, and autoimmune disorders.

Learn about the Erythrocyte Sedimentation Rate (ESR) test procedure, which is used to diagnose and monitor conditions like inflammation, infection, cancer, and autoimmune disorders. Explore the steps involved, from pre-test procedures and blood collection to clotting and reading the results. Understand how factors like medication use can affect the accuracy of ESR test results.