The erythrocyte sedimentation rate (ESR) blood test is done to check for diseases causing inflammation in your child’s body. The test measures how many of your child’s red blood cells (erythrocytes) fall to the bottom of a test tube in 1 hour. When inflammation is present, red blood cells clump together and fall more quickly to the bottom.
The ESR is also called the sedimentation rate, or sed rate.
The ESR test may help diagnose and treat a medical problem your child is having. It does not diagnose a specific problem but it can help the healthcare provider know what other tests your child might need. It’s also a way to see how well treatment for a disease is working.
Your child's healthcare provider makes a tiny cut in a baby's heel to get a small amount of blood to test. A small amount of blood is taken from a finger with a fingerstick or from a vein in your child’s arm with a needle. The blood is collected in tubes and sent to a lab.
Ask your healthcare provider when and how you will get the result of your child’s test.
When there is inflammation in the body, the red blood cells stick together more than normal and fall to the bottom of the test tube more quickly. This means that more of them fall to the bottom of the test tube in 1 hour than when there is no inflammation. Your child’s ESR may be higher than normal if he has a disease or problem that is causing inflammation, such as:
Some diseases cause inflammation but do not raise the ESR, so a normal result does not always mean that your child does not have a medical problem. A low ESR is usually not a problem. However, your ESR may be lower than normal if your child has:
If your child is being treated for an inflammatory disease, an ESR that is going down is often a good sign that his body is responding to the treatment.
Test results are only one part of a larger picture that takes into account your child’s medical history and current health. Sometimes a test needs to be repeated to check the first result. Talk to your healthcare provider about the result and ask questions, such as: