Sed rate (erythrocyte sedimentation rate)
About this test
Sed rate, or erythrocyte sedimentation rate (ESR), is a blood test that can show inflammatory activity in the body. Many health problems can cause a sed rate test result to be outside the standard range. A sed rate test is often used with other tests to help your health care team diagnose or check the progress of an inflammatory disease.
Why it's done
A sed rate test may be ordered if you have symptoms like unexplained fever, muscle pain or joint pain. The test can help confirm a diagnosis of certain conditions, including: Giant cell arteritis. Polymyalgia rheumatica. Rheumatoid arthritis. A sed rate test also can help show the level of your inflammatory response and check the effect of treatment. Because a sed rate test can't pinpoint the problem that's causing inflammation in your body, it's often accompanied by other blood tests, such as the C-reactive protein (CRP) test.
How to prepare
The sed rate is a simple blood test. You don't need to fast before the test.
What to expect
During a sed rate test, a member of your health care team will use a needle to take a small sample of blood from a vein in your arm. This often takes just a few minutes. Your blood sample is sent to a lab for testing. After the test, your arm might be tender for a few hours, but you'll be able to resume most normal activities.
Understanding your results
Results from your sed rate test will be reported in the distance in millimeters (mm) that red blood cells have fallen in the test tube in one hour (hr). Age, sex and other factors can affect the sed rate results. Your sed rate is one piece of information to help your health care team check your health. Your team will also take into consideration your symptoms and your other test results.
Disclaimer: August is a health information platform and its responses don't constitute medical advise. Always consult with a licenced medical professional near you before making any changes.