ESR stands for erythrocyte sedimentation rate. It is also known as the “sed rate” or the “sedimentation rate.” Doctors will recommend an ESR test to determine and evaluate the severity of inflammations occurring in the body, which include different types of infections, cancers, and autoimmune diseases and syndromes. It is an easy-to-conduct and non-specific test that is relatively cost effective as opposed to other kinds of blood tests.
ESR tests were more commonly used in the days gone by as compared to today; because more-pertinent tests of inflammatory activity are currently available. Now, a doctor will usually suggest an ESR test if he/she suspects the presence of polymyalgia rheumatic, giant cell arteritis, or rheumatoid arthritis. A sedimentation rate test may also aid in ascertaining the degree of inflammatory reactions and screen the effect of therapies.
It may also be noted that an ESR blood test comes with certain limitations such as inability to find the precise site of medical anomaly in the body, and failure to ascertain the cause of inflammation. It is therefore considered as a non-specific test that can be used as a helpful tool to check the progress of varied inflammatory conditions affecting the body. Due to the restricted applications of an ESR blood test it is normally performed in conjunction with numerous other diagnostic tests, like the C-reactive protein test/CRP test, for proper diagnosis and conclusive results.The ESR is a simple serum test and patients do not have to fast prior to the test.
How is an ESR blood test performed?
Completely developed blood cells that contain hemoglobin are referred to as erythrocytes. Hemoglobin are proteins that perform the function of carrying oxygen-rich blood from the lungs to different parts of the body. The name ESR blood test, or erythrocyte sedimentation rate test is thus self-explanatory. It explains the sedimentation process of erythrocytes.
An ESR test starts with the collection of a blood sample. The blood is taken out from the vein present in a patient’s arm. The sample is then kept in a tube which remains in an upright position without being disturbed any further.
With the passage of time, red blood cells begin their descent to the bottom of the tube at their own speed. This speed, or rate of descent of the blood cells is instrumental in determining the ESR reading. The ESR value is measured and written down in mm/hr., i.e., millimeters per hour. In lay man’s terms, the ESR value refers to the distance (in mm) covered by the red blood cells over a period of one hour.
A person affected by any type of inflammatory condition will experience elevated levels of fibrinogen. This makes the red blood cells stick to one another. Later, the blood cells will create stacks known as rouleaux. This matter has a general tendency to descend at a faster pace. Thus, we can conclude that a faster rate of descent of red blood cells is most likely to indicate the occurrence of inflammation in the body.
Normal range in an ESR blood test
The ESR blood test normal range values in mm/hr. are given below and categorized according to the gender and age:
- For men over 50 years, the normal ESR reading is below 20
- For men younger than 50 years, the normal ESR reading is below 15
- For women above 50 years, the normal ESR reading is below 30
- For women younger than 50 years, the normal ESR reading is below 20
- For newborns, the normal ESR reading varies between 0 and 2
- For neonatal till puberty, the normal ESR reading varies between 3 and 13
The ESR readings/values listed above signify the normal range. It may however be noted that abnormal ESR values may result due to numerous factors. Such factors are detailed below.
An ESR reading that is above the normal range
When the ESR value increases moderately or mildly from the normal range, then it can be considered as a sign of inflammation in the body and the occurrence of varied conditions like anemia, pregnancy, aging, cardiac abnormalities, diabetes, and certain kinds of infections.
When there is a very high increase in the ESR value as compared to the normal range, then it can be considered as a sign of serious inflammation in the body, severe infections, bone marrow tumor or multiple myeloma, cancer which affects the immune system cells, inflammatory complications that affect the muscles, and temporal arteries inflammation which results in symptoms such as occasional impaired vision, headaches, and problematic chewing.
When the ESR value increases at a steady pace from the normal rangein subsequent tests, then it can be considered as a sign of inflammation in the body that is gradually becoming serious.
An ESR reading that is below the normal range
An ESR value that is below the normal range is of no great importance. It can however be considered as a sign of different disorders such as polycythemia, sickle cell anemia, serious leukocytosis, and protein anomalies.
ESR blood tests were carried out in the past as more efficient means of measuring body inflammations were not available.
It may however be noted that the presence of varied diseases, disorders, and medical conditions listed in the sections above can lead to abnormal ESR test results. The abnormalities can either increase the ESR values or decrease it below the normal range. It is also important to remember that the above mentioned diseases are not the only abnormalities. A number of other medical complications can also affect the ESR test values.
It is therefore mandatory for all patients to consult a physician about the ESR test results. It is also important for patients to discuss all the details about their current consumption of any OTC or prescription drugs during such consultations.