NOTE: Due to the special handling of your specimen necessary for this particular test, it is recommended that you DO NOT have your blood drawn on a Friday. Going Mon-Thu will enable the draw site to overnight your specimen to the lab so it will arrive PRIOR to the weekend.

Synonyms: Erythrocyte Sedimentation Rate; ESR; Westergren Sedimentation Rate

NOTICE: This is a component of the Arthritis Panel which may be more appealing than ordering this test alone.

Why It Is Done

*Determine whether a condition causing inflammation is present.*Monitor the response to treatment of some conditions, such as an infection or some autoimmune diseases.

Test Overview

The sedimentation rate (sed rate) blood test measures how quickly red blood cells (erythrocytes) settle in a test tube in one hour.

When inflammation is present in the body, certain proteins cause red blood cells to stick together and fall more quickly than normal to the bottom of the tube. The more red cells that fall to the bottom of a special test tube in one hour, the higher the sed rate. These proteins are produced by the liver and the immune system under many abnormal conditions, such as an infection, an autoimmune disease, or cancer.

How To Prepare

No special preparation is necessary.