Erythrocyte Sedimentation Rate (ESR)

Why this test may be ordered

• To help diagnose conditions that cause inflammation, such as arthritis, vasculitis, infections, and inflammatory bowel diseases
• To monitor an existing condition that causes inflammation
• When you have symptoms of inflammation like headaches, unexplained fever, unexplained weight loss, joint stiffness, neck or shoulder pain, loss of appetite, or anemia

Preparation and collection

You don't need any special preparations for this test. However, if your provider ordered other tests on your blood sample, you may need to fast (not eat or drink) for several hours before the test. Your provider will let you know if there are any special instructions.

A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. This usually takes less than five minutes.

There is very little risk to having an ESR. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.

Understanding results

Your provider will use your ESR test results, medical history, symptoms, and other test results to make a diagnosis. An ESR test alone cannot diagnose conditions that cause inflammation. Normal ESR levels vary depending on your age and sex.

• High ESR (faster than normal sedimentation): May indicate a condition that causes inflammation, such as giant cell arteritis, arthritis, systemic vasculitis, polymyalgia rheumatica, inflammatory bowel disease, kidney disease, infections, rheumatoid arthritis, autoimmune diseases, heart disease, or certain cancers. Limitation: A high ESR cannot diagnose which specific condition is causing inflammation. Many non-disease factors (e.g., pregnancy, menstrual cycle, aging, obesity, regular alcohol use, exercise) and certain medicines can also raise ESR. Next step: Your provider will consider your symptoms, medical history, and other test results (such as a C-reactive protein test) to determine the cause and next steps.
• Low ESR (slower than normal sedimentation): May be caused by conditions such as polycythemia (increased red blood cells), sickle cell disease, leukocytosis (high white blood cell count), heart failure, or certain kidney and liver problems. Limitation: A low ESR alone cannot diagnose these conditions. Non-disease factors and medications can also affect ESR results. A normal ESR does not rule out inflammation. Next step: Your provider will interpret your low ESR in the context of your overall health, symptoms, and other laboratory tests to reach a diagnosis.

• An ESR test alone cannot diagnose which condition is causing inflammation.
• It is possible to have a condition that causes inflammation and still have a normal ESR result.
• Normal ESR levels vary based on age and sex.
• Factors like pregnancy, menstrual cycle, aging, obesity, regular alcohol consumption, exercise, and certain medicines or supplements can affect ESR results.
• The test does not provide a specific diagnosis; it is a nonspecific marker of inflammation.

What to do next

If your ESR results are not normal, it does not always mean you have a medical condition that needs treatment. Your provider will use your ESR results along with your medical history, symptoms, and other tests (such as a C-reactive protein test) to make a diagnosis and determine the next steps. Discuss all results and concerns with your healthcare provider.

• Do I need to do anything special to prepare for an ESR test?
• What are the risks or side effects of having an ESR blood draw?
• What does it mean if my ESR result is high?
• Can my ESR be normal even if I have inflammation?
• What other tests might my provider order along with an ESR?

Evidence source

U.S. National Library of Medicine: Erythrocyte Sedimentation Rate (ESR)