What is an Erythrocyte Sedimentation Rate?
An erythrocyte sedimentation rate (ESR) test is sometimes called a sedimentation rate test or sed rate test. This blood test does not diagnose one specific condition. Instead, it helps our healthcare providers determine whether you are experiencing inflammation. The test is done to check for diseases causing inflammation in your body. It measures how many of your red blood cells (erythrocytes) fall to the bottom of a test tube in 1 hour. Our doctor will look at ESR results along with other information or test results to help figure out a diagnosis. The tests requested will depend on your symptoms.
Why would I need this test?
You may need this test if you have symptoms of one of the diseases that may cause ESR to go up. These include:
- Headaches
- Fever
- Weight loss
- Joint stiffness
- Neck or shoulder pain
- Loss of appetite
- Anemia
The test will allow our doctors to be able figure out a diagnosis see how well they can treat and how well you are responding to treatment after the diagnosing.
How do I prepare for an ESR test?
You may need to avoid taking certain medicines before the test because they might affect the test result. Make sure you inform our doctors about any medicines, herbs, or supplements that you are taking. You can ask our doctors before stopping any of your regular medicines. Talk to our doctors if you have any questions about the test. It can be done at any time of the day.
How is an ESR performed?
This test involves a simple blood draw. It should take only a minute or two.
- First, the skin directly over your vein is cleaned.
- Then, a needle is inserted to collect your blood.
- After collecting your blood, the needle is removed and the puncture site covered to stop any bleeding.
The blood sample is taken to a lab, where your blood will be placed in a long, thin tube in which it sits to gravity for one hour. During and after this hour, the laboratory professional processing this test will assess how far the RBCs sink into the tube, how quickly they sink, and how many sink.
Inflammation can cause abnormal proteins to appear in your blood. These proteins cause your RBCs to clump together. This makes them fall more quickly.
The ESR for children
There is very little difference between children’s veins and adult veins. Therefore the procedure is very similar. Children can be quite scared of needles, though, so it is important that the parent and medical practitioner both encourage the child to remain calm and relaxed. You may wish to explain to the child that it only stings for a very short time, and offer them a treat afterwards.
Blood sample analysis
The analysis of the collected blood is carried out automatically by a machine in a pathology laboratory. The laboratory will send the results to our doctors'.
>What do the results of my ESR test mean?
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.
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
Your ESR may be higher than normal if you have a disease or problem that is causing inflammation, such as:
- Arthritis
- Autoimmune disease (a disease that causes your body to attack your own tissues, like lupus)
- Infection
- Cancer
The ESR is also higher during pregnancy or if you have kidney or thyroid disease. Our doctors will use the result of your ESR test, the history of your illness, your physical exam, and any other tests you may have had to arrive at a diagnosis. Some diseases cause inflammation but do not raise the ESR, so a normal result does not always mean that you do not have a medical problem.
A low ESR is usually not a problem. However, your ESR may be lower than normal if you have:
- A disease or condition that increases red blood cell production
- A disease or condition that increases white blood cell production
- Sickle cell anemia (abnormal red blood cells)
If you are being treated for an inflammatory disease, an ESR that is going down is a good sign that your body is responding to the treatment.
Are there any risks to the test?
The ESR test is simple and quick, taking just a few minutes to complete. The procedure is very safe and poses few risks.
People who take the test may feel a slight sting when the needle pricks the arm. Some people may bleed slightly where the needle pierces the skin, and others may feel temporarily faint or dizzy.
After the test, people may get a small bruise at the puncture site or experience mild soreness in the arm, which can last for a few days. In more sensitive people, this bruising may turn into a hematoma.
