WellSpan Home

Health Library

Erythrocyte Sedimentation Rate

Does this test have other names?

ESR, sed rate

What is this test?

Erythrocyte sedimentation rate (ESR) is a blood test. It measures how quickly erythrocytes, or red blood cells, separate from a blood sample that has been treated so the blood will not clot. During this test, a small amount of your blood will be put in an upright tube. A lab specialist will measure the rate that your red blood cells settle toward the bottom of the tube after 1 hour.

If you have a condition that causes inflammation or cell damage, your red blood cells tend to clump together. This makes them heavier, so they settle faster. The faster your red blood cells settle and fall, the higher your ESR. A high ESR tells your healthcare provider that you may have an active disease process in your body. 

Why do I need this test?

You may need this blood test if you have symptoms of one of the diseases that may cause ESR to go up.

You may also need this test if you have already been diagnosed with a disease that causes a high ESR. The test can allow your healthcare provider to see how well you are responding to treatment.

The ESR blood test is most useful for diagnosing or monitoring diseases that cause pain and swelling from inflammation. Other symptoms may include fever and weight loss. These diseases include:

  • Temporal arteritis

  • Rheumatoid arthritis

  • Polymyalgia rheumatica

ESR is not used as a screening test in people who do not have symptoms or to diagnose disease because many conditions can cause it to increase. It might also go up in many normal cases. ESR doesn't tell your healthcare provider whether you have a specific disease. It only suggests that you may have an active disease process in your body. 

What other tests might I have along with this test?

You may have other tests if your healthcare provider is doing this test to diagnose a disease.

Your provider may do an ESR alone if he or she is monitoring a disease you already have.

Because ESR tells your provider only what is happening right now, you may need to have the test repeated over time. 

What do my test results mean?

A result for a lab test may be affected by many things, including the method the laboratory uses to do the test. If your test results are different from the normal value, you may not have a problem. To learn what the results mean for you, talk with your healthcare provider.

ESR is measured in millimeters per hour (mm/h). The normal values are:

  • 0 to 10 mm/h in children

  • 0 to 15 mm/h in men younger than 50

  • 0 to 20 mm/h in men older than 50

  • 0 to 20 mm/h in women younger than 50

  • 0 to 30 mm/h in women older than 50

ESR above 100 mm/h is most likely caused by an active disease. For instance, you may have:

  • A disease that causes inflammation in your body

  • Active infection

  • Cancer

  • Heart disease

  • Kidney disease

  • Blood disease

  • Diabetes

  • Collagen vascular disease

How is this test done?

The test requires a blood sample, which is drawn through a needle from a vein in your arm.

Does this test pose any risks?

Taking a blood sample with a needle carries risks that include bleeding, infection, bruising, or feeling dizzy. When the needle pricks your arm, you may feel a slight stinging sensation or pain. Afterward, the site may be slightly sore. 

What might affect my test results?

Many things that are not active diseases can increase your ESR. These include:

  • Pregnancy

  • Old age

  • Being female

  • Having a menstrual period

  • Having recently eaten a fatty meal

  • Being obese

  • Taking certain medicines

How do I get ready for this test?

You don't need to prepare for this test. Be sure your healthcare provider knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illicit drugs you may use. Tell your provider if you ate a fatty meal recently, if you are having your period, or if you may be pregnant. 

Erythrocyte Sedimentation Rate - WellSpan Health

Author: Iliades, Chris, MD
Online Medical Reviewer: Sather, Rita, RN
Online Medical Reviewer: Snyder, Mandy, APRN
Last Review Date: 2015-08-23T00:00:00
Last Modified Date: 2015-09-04T00:00:00
Published Date: 2015-09-04T00:00:00
Last Review Date: 2012-04-25T00:00:00
© 2016 WellSpan Health. All Rights Reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.

I would like to:

Are you sure you would like to cancel?

All information will be lost.

Yes No ×

About the provider search

This search will provide you with WellSpan Medical Group and Northern Lancaster County (Ephrata) Medical Group primary care physicians and specialists. If we don’t have a WellSpan Medical Group physician to meet your criteria, the search will expand to include community physicians who partner with WellSpan Medical Group physicians through the WellSpan Provider Network or provide care to patients on the Medical Staffs of WellSpan’s Hospitals.


Schedule Your Next Appointment Online with MyWellSpan

Use your MyWellSpan patient portal any time to view available appointments, and pick the date and time that best suits your schedule.

Go to MyWellSpan

New to this practice?

If you don't have a WellSpan primary care provider and would like to schedule a new patient appointment with a provider who is accepting patients, just log into your MyWellSpan account, and go to the Appointment Center section. As you progress through the scheduling process, you will be able to see the offices that are accepting new patients in relation to your zip code. If you are not enrolled in MyWellSpan, go to https://my.wellspan.org, call 1-866-638-1842 or speak with a member of the staff at a participating facility to sign up. New patient scheduling not available at all practices/programs.

Already a patient at this practice?

If you already have a relationship with a WellSpan practice, simply log into your account, and go to the Appointment Center section. As you progress through the scheduling process, you will be able to schedule an appointment with any provider or practice that already counts you as a patient. Online scheduling varies by practice/program.