The erythrocyte sedimentation rate (ESR) is a blood test that can detect inflammation in your body. Inflammation is the immune system's reaction to damage, infection, and various illnesses, including immune system disorders, certain malignancies, and blood problems.
Explaining the ESR test
Erythrocytes are red blood cells. A blood sample is sent to a laboratory to perform an ESR test. A healthcare expert places the sample in a tall, thin test tube and examines how the red blood cells settle or sink to the bottom. Typically, red blood cells fall slowly. However, inflammation causes red blood cells to stay together in clumps. These cell aggregates sink faster because they are heavier than single cells.
If an ESR test reveals that your red blood cells sink faster than usual, it could indicate a medical issue causing inflammation. The quickness of your test result shows how much inflammation you have.
Other names for an ESR test are ESR, SED rate sedimentation rate, and Westergren sedimentation rate.
What exactly is it used for?
An ESR test can be performed in conjunction with other tests to assist in determining inflammation-causing illnesses. It can also be used to help track these problems. Several illnesses produce inflammation, including arthritis, vasculitis, infection, and inflammatory bowel disease. An ESR can also be used to track an ongoing ailment.
What information can the ESR test reveal?
The factors and diseases listed here are typically related to unusual ESR readings. Consult your doctor or health care expert to get an accurate diagnosis.
1) Inflammation
The ESR test determines whether you have inflammation.
Some proteins, such as fibrinogen, emerge in the bloodstream during inflammation. These proteins cause red blood cells to bind together and form clumps. This makes them heavier, so they fall faster, raising the ESR. Therefore, a high ESR indicates inflammation. A high ESR level means high inflammation.
2) Screening for specific diseases.
The ESR test might help in the identification of specific diseases:
- Polymyalgia rheumatica is an inflammatory condition that causes muscle discomfort and stiffness.
- Giant cell arteritis is an inflammation of the blood arteries.
- Cancer
- Bone infections.
- Subacute thyroiditis (thyroid inflammation).
- Ulcerative Colitis
3) Progress of Specific Conditions
The ESR test can not diagnose diseases, but it can track the progression of specific conditions:
- Heart disease Cancer
- Rheumatoid arthritis.
- Systemic lupus erythematosus.
- Sickle cell illness.
4) Serious conditions.
- ESR levels greater than 100 mm/hr may indicate a dangerous condition, such as infection, heart disease, or malignancy.
- ESR levels higher than usual may indicate malignancy or cancer development, such as metastasis.
What exactly happens during an ESR?
A healthcare provider will use a tiny needle to draw blood from a vein in your arm. After the needle is placed, a small amount of blood is drawn into a test tube or vial. When the needle is inserted or removed, you may experience a mild sting. This usually takes under five minutes.
The Westergren Method
The Westergren method is considered the gold standard for measuring ESR. The blood sample is diluted with sodium citrate (4:1). The mixture is then transferred to a Westergren-Katz tube with a diameter of 2.5 mm until it reaches 200 mm. Next, the tube is placed vertically at room temperature (18 - 25 °C) for an hour. After an hour, they measure how far the red blood cells have settled. This is the ESR distance. The modified Westergren method uses edetic acid instead of sodium citrate.
Will I need to prepare for an ESR?
There are no extra preparations required for this test. However, if your provider has ordered additional tests on your blood sample, you may need to fast (no eating or drinking) for several hours before the test. Your provider will notify you if there are any particular instructions to follow.
What do the results indicate?
Your provider will determine a diagnosis based on the results of your ESR test and your medical history, symptoms, and other tests. An ESR test cannot diagnose inflammatory diseases.
A high ESR test result could indicate an inflammatory condition, such as:
- Arteritis
- Arthritis
- Systemic vasculitis
- Polymyalgia rheumatica
- Inflammatory bowel disease
- Kidney disease
- Infection
- Rheumatoid arthritis and other autoimmune diseases
- Heart disease
- Certain cancers
A low ESR test result indicates that your red blood cells sank more slowly than expected. This could be caused by circumstances like:
- A blood disorder, such as:
- Polycythemia
- Sickle cell disease (SCD)
- Leukocytosis, a very high white blood cell count (WBC)
- Heart failure
- Certain kidney and liver problems
If your ESR readings are abnormal, it does not necessarily indicate that you have a medical issue that requires treatment. Pregnancy, menstruation, ageing, obesity, regular alcohol consumption, and exercise can all affect ESR results. Specific medications and supplements may also alter your results.
Because an ESR cannot diagnose a specific disease, your doctor may perform additional tests simultaneously. For your health, you must choose the best. At Agilus, you get world-class facilities, and our experts will guide you at every stage to make your experience smoother. Visit our website or give us a call to learn more about an ESR test.
