Erythrocyte Sedimentation Rate Test (ESR Blood Test)

What is the Erythrocyte Sedimentation Rate (ESR) Test?

Inflammation is one of the body's normal immune responses to any injury or infection. It can be secondary to an immune disorder or a chronic disease. Under normal conditions, red blood cells, or erythrocytes, settle slowly to the bottom of a test tube containing a blood sample. The ESR blood test measures how rapidly the blood settles in a test tube. It is a blood test that can reveal inflammatory activity in the body. It is also known as the SED rate, sedimentation rate, ESR, and Westergren sedimentation rate.

When is the Erythrocyte Sedimentation Rate (ESR) Test Prescribed?

A doctor may recommend this test in the following.

• To detect the cause of pain in the patients

• To detect the conditions causing inflammation, like vasculitis, arthritis, or inflammatory bowel disease

• As a part of routine investigation

• In patients suffering from Rheumatoid arthritis

• In patients with cardiac or kidney disease

• To detect the cause of fever

• In autoimmune diseases

What are the components of the Erythrocyte Sedimentation Rate (ESR) Test?

This test can be done alone or as part of a complete blood count. Conditions that cause inflammation are included in this test.RBCs, also known as erythrocytes, are used in an ESR test to gauge how rapidly they settle to the bottom of a test tube. Sedimentation, measured in millimeters per hour (mm/h), is the process by which these cells descend.

What is the usual range of the Erythrocyte Sedimentation Rate (ESR Test?

The normal range is 

Women: 0 to 29 mm/hr 

Men: 0 to 22 mm/hr 

A Low ESR rate indicates

• Cardiac disease

• Liver problem

• RBC disorders

• Kidney disease

A high ESR indicates

• Anemia

• Kidney disease

• Cancer 

• Tissue injury

• Arthritis

• Infections

Preparation and Perquisites

No specific preparation is required for an ESR blood test. However, if you are scheduled for additional blood tests at the same time, some preparation may be necessary. It’s best to confirm with your doctor or the pathology collection centre beforehand to ensure you follow any required instructions. During the test, below are the following steps are followed.

• A blood sample is taken from the vein,

• The RBCs in the test tube are monitored for one hour to determine the ESR.

• The report comes within a few hours of the test.

• Some doctors recommend fasting before the test

• The test is not diagnostic, but, of course, is an indication of underlying pathology which needs to be further evaluated