What is ESR?
ESR is an abbreviated form for erythrocyte sedimentation rate. It is often referred to as the sedimentation rate or the sed rate. An ESR blood test is usually done to check and understand the degree of inflammation in the body such as cancers, various kinds of infections as well as autoimmune disorders and diseases. It is a non specific and an easy test which is really cost effective as compared to other blood tests.
An ESR blood test has some limitations which includes facts such as an inability to determine the cause of inflammation in the body as well as the exact location of the medical abnormality. Hence it is a non specific test, but can be used as an aiding tool to monitor the progress of any inflammatory disease in the body.
Due to the limited applicability of the ESR blood test, it is usually carried out along with several other tests to arrive at conclusive results and diagnosis.
The ESR blood test: An explanation
The erythrocytes are the fully grown blood cells that have hemoglobin which facilitates the process of carrying oxygen from the lungs to the various organs and tissues of the body. Therefore, the name i.e. erythrocyte sedimentation rate or ESR itself conveys the meaning, which refers to the sedimentation process of the erythrocytes.
The ESR test commences with the collection of a sample of blood that is drawn from the vein in the arm of the patient. The blood sample is then placed in a tube which is left in an upright arrangement without any further disturbance.
Over the course of time the red blood cells start descending at their own pace. This pace or rate of descent of the red blood cells in an hour is what determines the ESR value. The ESR value is reported and measured in mm/hr or millimeters per hour. In other words, the distance (in millimeters) that is travelled by the red blood cells in one hour comprises the ESR value.
When the body is afflicted by any form of inflammation, then it leads to excessive proportion of fibrinogen. This causes the red blood cells to attach to one another. Afterwards, the blood cells produce stacks called rouleaux. Such substances have a general tendency to descend faster. Hence, the faster the red blood cells settle, the greater are the chances of increased inflammation in the body.
ESR blood test normal range
The normal ESR values in mm/hr are listed below and classified as per the age and gender.
- For men above 50 yrs the normal ESR value is below 20
- For men under 50 yrs the normal ESR value is below 15
- For women over 50 yrs the normal ESR value is below 30
- For women below 50 yrs the normal ESR value is below 20
- For newborns the normal ESR value ranges from 0 to 2
- For neonatal till puberty the normal ESR value ranges from 3 to 13
The above ESR values are indicative of the normal range. However, one must be aware of the fact that a number of factors can lead to abnormal ESR values. These factors are explained below
High ESR, value above the normal range
A mild or moderate increase from the normal values of ESR can be considered as an indication of bodily inflammations and the presence of other conditions such as anemia, aging, pregnancy, diabetes, cardiac diseases and some types of infections.
A very high increase from the normal ESR values can be considered as an indication of severe inflammations, extreme infections, cancer that affects the cells of the immune system, multiple myeloma or bone marrow tumor, inflammatory complications of the muscles as well as inflammation of the temporal arteries which can include chewing difficulties, headaches and on certain occasions impaired vision.
An ESR test that shows steadily rising results can be considered as an indication of inflammation that is slowly increasing.
Low ESR, value below the normal range
An ESR value that is under the normal range does not bear any major significance but can be considered as an indication of conditions such as sickle cell anemia, polycythemia, protein irregularities and extreme leukocytosis.
ESR tests were conducted in the past when better methods to measure body inflammations were unavailable.
However, the medical conditions that are mentioned above are some of the causes that may result in abnormal ESR test values. Such conditions can either bring down the ESR values or elevate it above the normal range. But one should be aware, that the above listed conditions are not the only ones. There can be several other conditions that can affect the ESR values.
Hence it is important to discuss the test results with the doctor. During consultations, it is also vital that individuals inform the doctor about the current intake of any prescription or over the counter medications.
Most of all, it is important to remember that an individual may be afflicted with certain medical conditions, but an ESR test will show normal results. It is the precise reason why an ESR test is not a stand-alone test and is usually conducted in conjunction with several other tests.