The ESR test, or erythrocyte sedimentation rate or erythrocyte sedimentation rate, is a blood test widely used to detect any inflammation or infection in the body, which may indicate from a simple cold, bacterial infections, to inflammatory diseases such as arthritis or acute pancreatitis, for example.
This test measures the speed of the separation between red blood cells and plasma, which is the liquid part of the blood, by the action of gravity. Thus, when there is an inflammatory process in the bloodstream, proteins are formed that decrease blood viscosity and accelerate the erythrocyte sedimentation rate, resulting in a high ESR, which is usually above 15 mm in men and 20 mm in women.
Thus, the ESR is a very sensitive test, as it can easily detect inflammation, but it is not specific, that is, it is not able to indicate the type, location or severity of the inflammation or infection that occurs in the body. Therefore, ESR levels must be assessed by the doctor, who will identify the cause according to the clinical evaluation and the performance of other tests, such as the CRP, which also indicates inflammation or blood count, for example.
What is it for
The VHS test is used to identify or assess any type of inflammation or infection in the body. Your result can identify:
1. High VHS
The situations that normally increase ESR are viral or bacterial infections, such as flu, sinusitis, tonsillitis, pneumonia, urinary tract infection or diarrhea, for example. However, it is widely used to assess and control the evolution of some diseases that alter its outcome in a more significant way, such as:
- Polymyalgia rheumatica which is an inflammatory disease of the muscles; Temporal arteritis which is an inflammatory disease of the blood vessels; Rheumatoid arthritis which is an inflammatory disease of the joints; Vasculitis, which are inflammations of the blood vessel wall; Osteomyelitis which is an infection of the bones; Tuberculosis which is an infectious disease; Cancer.
In addition, it is important to remember that any situation that changes the blood dilution or composition can change the test result. Some examples are pregnancy, diabetes, obesity, heart failure, kidney failure, alcoholism, thyroid disorders or anemia.
2. low ESR
The low ESR test usually does not indicate changes. However, it is important to remember that there are situations that can keep ESR abnormally low, and confuse the detection of inflammation or infection. Some of these situations are:
- Polycythemia, which is an increase in blood cells; Severe leukocytosis, which is an increase in white blood cells in the blood; Use of corticosteroids; Hypofibrinogenesis, which is a blood clotting disorder; Hereditary spherocytosis, which is a type of anemia that goes on from parents to children.
Thus, the doctor must always see the value of the ESR test and analyze it according to the person's clinical history, as its result is not always compatible with the health situation of the person evaluated. The doctor may also use newer and more specific tests, such as PCR, which usually indicates more specifically situations such as infection. Find out what the PCR exam is and how it is done.
How is done
To perform the VHS test, the laboratory will collect a blood sample, which is placed in a closed container, and then it will be evaluated how long it takes for the red blood cells to separate from the plasma and settle to the bottom of the container.
Thus, after 1 hour or 2 hours, this deposition will be measured, in millimeters, so the result is given in mm / h. To perform the VHS exam, no preparation is necessary, and fasting is not mandatory.
Reference values
The reference values of the VHS exam are different for men, women or children.
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In men:
- in 1h - up to 15 mm; in 2h - up to 20 mm.
- in 1h - up to 20 mm; in 2h - up to 25 mm.
- values between 3 - 13 mm.
Currently, the values of the VHS exam in the first hour are the most important, so they are the most used.
The more intense the inflammation, the more the ESR can rise, and rheumatological diseases and cancer can cause inflammation so severe that it is capable of increasing the ESR above 100 mm / h.
