At a Glance
Why Get Tested?
To detect the presence of inflammation caused by one or more conditions such as infections, tumors or autoimmune diseases; to help diagnose and monitor specific conditions such as temporal arteritis, systemic vasculitis, polymyalgia rheumatica, or rheumatoid arthritis
When to Get Tested?
When your health practitioner thinks that you might have a condition causing inflammation; when you have signs and symptoms associated with temporal arteritis, systemic vasculitis, polymyalgia rheumatica, or rheumatoid arthritis such as headaches, neck or shoulder pain, pelvic pain, anemia, poor appetite, unexplained weight loss, and joint stiffness
A blood sample drawn from a vein in your arm
Test Preparation Needed?
The Test Sample
What is being tested?
Erythrocyte sedimentation rate (ESR or sed rate) is a test that indirectly measures the degree of inflammation present in the body. The test actually measures the rate of fall (sedimentation) of erythrocytes (red blood cells) in a sample of blood that has been placed into a tall, thin, vertical tube. Results are reported as the millimeters of clear fluid (plasma) that are present at the top portion of the tube after one hour.
When a sample of blood is placed in a tube, the red blood cells normally settle out relatively slowly, leaving little clear plasma. The red cells settle at a faster rate in the presence of an increased level of proteins, particularly proteins called acute phase reactants. The level of acute phase reactants such as C-reactive protein (CRP) and fibrinogen increases in the blood in response to inflammation.
Inflammation is part of the body's immune response. It can be acute, developing rapidly after trauma, injury or infection, for example, or can occur over an extended time (chronic) with conditions such as autoimmune diseases or cancer.
The ESR is not diagnostic; it is a non-specific test that may be elevated in a number of these different conditions. It provides general information about the presence or absence of an inflammatory condition.
There have been questions about the usefulness of the ESR in light of newer tests that have come into use that are more specific. However, ESR test is typically indicated for the diagnosis and monitoring of temporal arteritis, systemic vasculitis and polymyalgia rheumatica. Extremely elevated ESR is useful in developing a rheumatic disease differential diagnosis. In addition, ESR may still be a good option in some situations, when, for example, the newer tests are not available in areas with limited resources or when monitoring the course of a disease.
How is the sample collected for testing?
A blood sample is obtained by inserting a needle into a vein in the arm.
NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.
Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.
Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed.
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NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.
Sources Used in Current Review
Henry's Clinical Diagnosis and Management by Laboratory Methods. 22nd ed. McPherson R, Pincus M, eds. Philadelphia, PA: Saunders Elsevier: 2011, Pp 519-521.
Wu a, et al. Antiquated Tests Within the Clinical Pathology Laboratory. Am J Manag Care. 2010;16(9):e220-e22. Available online at http://www.ajmc.com/publications/issue/2010/2010-09-vol16-n09/AJMC_10sep_Wu_Xcl_e220to227 through http://www.ajmc.com. Accessed February 2014.
(November 2012) Saenger A, Block D. C-Reactive Protein and Erythrocyte Sedimentation Rate Testing: Should Both Be Ordered? Mayo Clinic Communique. Available online at http://www.mayomedicallaboratories.com/articles/communique/2012/11utiliz.html through http://www.mayomedicallaboratories.com. Accessed February 2014.
(September 30, 2013) Fran Lowry. Inflammatory Markers Elevated in Patients With Stable Pain. Medscape Medical News. Available online at http://www.medscape.com/viewarticle/811874 through http://www.medscape.com. Accessed February 2014.
(Updated: Feb 15, 2012) Lin J. Erythrocyte Sedimentation Rate. Medscape Reference article. Available online at http://emedicine.medscape.com/article/2085201-overview#a30 through http://emedicine.medscape.com. Accessed February 2014.
Curvers J, et al. Evaluation of the Ves-Matic Cube 200 Erythrocyte Sedimentation Method Comparison With Westergren-Based Methods. (2010) American Journal of Clinical Pathology, 134, 653-660. Available online at http://ajcp.ascpjournals.org/content/134/4/653.long through http://ajcp.ascpjournals.org. Accessed February 2014.
(February 18, 2003) Paget S. CRP and Inflammatory Diseases. Medscape Reference. Available online at http://www.medscape.com/viewarticle/449312 through http://www.medscape.com. Accessed February 2014.
Stojan G, et al. Erythrocyte sedimentation rate is a predictor of renal and overall SLE disease activity, Lupus. 2013 July; 22(8): 10. Available online at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3703841/ through http://www.ncbi.nlm.nih.gov. Accessed February 2014.
Kermani TA, et al. Utility of erythrocyte sedimentation rate and C-reactive protein for the diagnosis of giant cell arteritis. Semin Arthritis Rheum. 2012 Jun;41(6):866-71. Available online at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3307891/ through http://www.ncbi.nlm.nih.gov. Accessed February 2014.
Sources Used in Previous Reviews
Brigden, M (October 1, 1999). Clinical Utility of the Erythrocyte Sedimentation Rate. American Family Physician: American Academy of Family Physicians. Available online at http://www.aafp.org/afp/991001ap/1443.html through http://www.aafp.org.
Shojania, Kam (2000). Rheumatology: 2. What laboratory tests are needed? Canadian Medical Association Journal: CMAJ 2000, 162(8):1157-63. Available online at http://www.cma.ca/cmaj/vol-162/issue-8/1157.htm#ery through http://www.cma.ca.
MEDLINEplus (October 3, 2001). Medical Encyclopedia: ESR. U.S. National Library of Medicine, Bethesda, MD. MEDLINEplus. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003638.htm.
Thomas, Clayton L., Editor (1997). Taber's Cyclopedic Medical Dictionary. F.A. Davis Company, Philadelphia, PA [18th Edition].
Pagana, Kathleen D. & Pagana, Timothy J. (1999). Mosby's Diagnostic and Laboratory Test Reference 4th Edition: Mosby, Inc., Saint Louis, MO.
Zlonis M: The mystique of the erythrocyte sedimentation rate - a reappraisal of one of the oldest laboratory tests still in use. Clin Lab Med 1993;13:787-800.
Henry's Clinical Diagnosis and Management by Laboratory Methods. 21st ed. McPherson R, Pincus M, eds. Philadelphia, PA: Saunders Elsevier: 2007, 465-466.
Pagana K, Pagana T. Mosby's Manual of Diagnostic and Laboratory Tests. 3rd Edition, St. Louis: Mosby Elsevier; 2006, 233-235.
Cha CH, et al (Aug 24, 2009). Erythrocyte Sedimentation Rate Measurements by TEST 1 Better Reflect Inflammation Than Do Those by the Westergren Method in Patients With Malignancy, Autoimmune Disease, or Infection. American Journal of Clinical Pathology. 2009;131(2):189-194. Available online at http://www.medscape.com/viewarticle/707423 through http://www.medscape.com. Accessed April 2010.
(May 7, 2009) Medline Plus Medical Encyclopedia: ESR. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003638.htm. Accessed April 2010.