The erythrocyte sedimentation rate (ESR) is a blood test revealing any inflammatory activity in the body. It is also known as the sed rate. The sed rate is not a stand-alone diagnostic tool. However, it would help the doctor to diagnose or monitor the progress of the inflammatory disease. When the blood sample is placed in a tall and thin tube, they gradually settle at the bottom. The cells can clump together due to inflammation. The clumps are denser than the individual cells, leading them to settle to the bottom much quicker. The sed rate test, i.e. the ESR blood test, would measure the distance the red blood cells would fall in a test tube in an hour. The farther the red blood cells descend, the greater would be the response of the immune system.
Why is the ESR blood test conducted?
The test might be conducted to evaluate the case of an unexplained fever. It can also be done for some types of arthritis and for symptoms that affect the muscles. This test also helps to confirm the diagnosis of certain conditions like the polymyalgia rheumatica, giant cell arteritis and rheumatoid arthritis. The sed rate test also helps to determine the severity of the inflammatory response and monitor the effect of the treatment. The sed rate test cannot pinpoint the problem that is causing the inflammation in the body. It would generally be accompanied by some other blood tests. The C-reactive protein (CRP) would be one such. The test might be combined with the TSH test, that is used to measure the levels of TSH in the blood. It helps to ensure that the thyroid is secreting is releasing the right amount of thyroxine into the bloodstream.
How would the ESR blood test proceed?
The ESR blood test is just a simple blood test, which means that there would be no need for a fasting. The medical assistant, nurse or the phlebotomist would use a needle to draw blood from the vein. This would be most likely in the arm. The site might become tender for a few hours. However, most of the normal activities can be resumed soon enough.
How can the results of the ESR blood test be comprehended?
The results from the ESR blood test would be reported in terms of speed. The distance would be reported in millimetres (mm) that the red blood cells descend in an hour (hr). The normal range would be 0 to 22 mm/hr for men, while it is 0 to 29 mm/hr for women. The upper threshold for the normal sed rate test often varies depending on what medical practice is undertaken. The sed rate test is a vital piece of information that aids the doctor to understand the status of the health. It is important to communicate with the doctor about what the sed rate implies. This, along with the symptoms and the results from the other diagnostic tests can help to identify the real problem. The SGPT test might also be recommended. This test is a good measure of the status of the liver and if it has sustained any damage.
Can the test results be affected in any way?
There are a number of conditions that affect the properties of the blood. This would affect how quickly the red blood cells sink in a sample of blood. This means the information about the inflammatory disease and what the doctor needs to understand from the sed rate test would be obscured by some other influencing factors. These complicating factors include:
- problems with the kidney
- some types of cancers like multiple myeloma
- an advanced age
- diseases with the thyroid
The doctor would be taking into account various complicating factors to interpret the results of the sed rate test.