What is an ESR test?
An erythrocyte sedimentation rate (ESR) test is sometimes called a sedimentation rate test or sed rate test. This blood test doesn’t diagnose one specific condition. Instead, it helps your healthcare provider determine whether you’re experiencing inflammation.
Your doctor will look at ESR results along with other information or test results to help figure out a diagnosis. The tests ordered will depend on your symptoms.
The ESR test can also be used to monitor inflammatory diseases.
Why do doctors request an ESR test?
When you’re experiencing inflammation, your red blood cells (RBCs) cling together, forming clumps. This clumping affects the rate at which RBCs sink inside a tube where a blood sample is placed.
The test lets your doctor see how much clumping is occurring. The faster and further the cells sink towards the bottom of a test tube, the more likely it is that inflammation is present.
The test can identify and measure inflammation, in general, in your body. However, it doesn’t help pinpoint the cause of inflammation. That’s why the ESR test is rarely performed alone. Instead, your doctor will likely combine it with other tests to determine the cause of your symptoms.
The ESR test can be used to help your healthcare provider diagnose conditions that cause inflammation, such as:
- autoimmune diseases