Health Encyclopedia

ESR

Definition

ESR stands for erythrocyte sedimentation rate. It is commonly called a "sed rate."

It is a test that indirectly measures the level of certain proteins in the blood. This measurement correlates with the amount of inflammation in the body.

Alternative Names

Erythrocyte sedimentation rate; Sed rate; Sedimentation rate

How the Test is Performed

A blood sample is needed. Most of the time, blood is drawn from a vein located on the inside of the elbow or the back of the hand. The blood sample is sent to a lab.

The test measures how fast red blood cells (called erythrocytes) fall to the bottom of a tall, thin tube.

How to Prepare for the Test

There are no special steps needed to prepare for this test.

How the Test will Feel

You may feel slight pain or a sting when the needle is inserted. You may also feel some throbbing at the site after the blood is drawn.

Why the Test is Performed

Reasons why a "sed rate" may be done include:

Unexplained fevers
Certain types of joint pain or arthritis
Muscle symptoms
Headache
Other vague symptoms that cannot be explained

This test may also be used to monitor whether an illness is responding to treatment.

This test can be used to monitor inflammatory diseases or cancer. It is not used to diagnose a specific disorder.

However, the test is useful for detecting and monitoring:

Autoimmune disorders
Bone infections
Certain forms of arthritis
Inflammatory diseases

Normal Results

For adults (Westergren method):

Men under 50 years old: less than 15 mm/hr
Men over 50 years old: less than 20 mm/hr
Women under 50 years old: less than 20 mm/hr
Women over 50 years old: less than 30 mm/hr

For children (Westergren method):

Newborn: 0 to 2 mm/hr
Newborn to puberty: 3 to 13 mm/hr

Note: mm/hr = millimeters per hour

Normal value ranges may vary slightly among different laboratories. Talk to your health care provider about the meaning of your specific test results.

What Abnormal Results Mean

An abnormal ESR may help with a diagnosis, but it does not prove that you have a certain condition. Other tests are almost always needed.

An increased ESR rate may occur in people with:

Anemia
Cancers such as lymphoma or multiple myeloma
Kidney disease
Pregnancy
Thyroid disease

The immune system helps protect the body against harmful substances. An autoimmune disorder is when the immune system mistakenly attacks and destroys healthy body tissue. ESR is often higher than normal in people with an autoimmune disorder.

Common autoimmune disorders include:

Very high ESR levels occur with less common autoimmune or other disorders, including:

Allergic vasculitis
Giant cell arteritis
Hyperfibrinogenemia (increased fibrinogen levels in the blood)
Macroglobulinemia - primary
Necrotizing vasculitis

An increased ESR rate may be due to some infections, including:

Bodywide (systemic) infection
Bone infections
Infection of the heart or heart valves
Rheumatic fever
Severe skin infections, such as erysipelas
Tuberculosis

Lower-than-normal levels occur with:

Congestive heart failure
Hyperviscosity
Hypofibrinogenemia (decreased fibrinogen levels)
Leukemia
Low plasma protein (due to liver or kidney disease)
Polycythemia
Sickle cell anemia

References

Pisetsky DS. Laboratory testing in the rheumatic diseases. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 242.

Vajpayee N, Graham SS, Bem S. Basic examination of blood and bone marrow. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 31.

Review Date:4/30/2021
Reviewed By:David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

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