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.
Erythrocyte sedimentation rate; Sed rate; Sedimentation rate
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.
There are no special steps needed to prepare for this test.
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.
Reasons why a "sed rate" may be done include:
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:
For adults (Westergren method):
For children (Westergren method):
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.
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:
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:
An increased ESR rate may be due to some infections, including:
Lower-than-normal levels occur with:
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.
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.