What is a sed rate (erythrocyte sedimentation rate or ESR) test?

Sed rate (erythrocyte sedimentation rate, also known as ESR) is a simple blood test that helps detect inflammation in the body. The test measures the rate of fall (sedimentation) of red blood cells (erythrocytes) in a sample of blood placed in a tall vertical tube. Increased sed rate indicates inflammation.

Sed rate tests are also used to monitor the progress of an inflammatory disease.

Inflammation may be linked to a number of conditions including infections, some cancers, and autoimmune diseases.

A sed rate test is done through blood taken by needle from a vein in your arm.

Why is a sed rate (erythrocyte sedimentation rate or ESR) test done?

A sed rate test may be done when your doctor suspects you have a condition causing inflammation. Sed rate is called a nonspecific test because it does not diagnose specific illnesses but adds to the information about the presence and levels of inflammation.

A sed rate may be ordered to help in diagnosing and monitoring conditions including:

Last reviewed by a Cleveland Clinic medical professional on 03/14/2018.


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