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.

References

  • Lab Tests Online. Erythrocyte Sedimentation Rate. Accessed 5/7/2018.
  • Cush JJ. Cush J.J. Cush, John J.Approach to Articular and Musculoskeletal Disorders. In: Kasper D, Fauci A, Hauser S, Longo D, Jameson J, Loscalzo J. Kasper D, Fauci A, Hauser S, Longo D, Jameson J, Loscalzo J Eds. Dennis Kasper, et al.eds. Harrison's Principles of Internal Medicine, 19e New York, NY: McGraw-Hill; 2014.
  • Common Laboratory Tests. In: LeBlond RF, Brown DD, Suneja M, Szot JF. LeBlond R.F., Brown D.D., Suneja M, Szot J.F. Eds. Richard F. LeBlond, et al.eds. DeGowin’s Diagnostic Examination, 10e New York, NY: McGraw-Hill; 2014.

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