Erythrocyte Sedimentation Rate (ESR/Sed Rate)
What Actually Is An ESR?
I think it's important to understand a little bit about the components of blood before we can understand what an ESR is. Blood that leaves your body, like if you cut your skin or have your blood drawn at the hospital, is called "whole blood." This "whole blood" (at the hospital) is drawn up into a syringe from your arm and is placed into a tube. The tube is sent down to the lab where it is placed in something called a centrifuge, which is a like a fancy carnival ride that spins the tube around in circles at a rate which would make any human being pass out. This allows the "whole blood" to be "spun down" into its three major components:
Plasma = Water + Proteins
Buffy coat = WBC + Platelets
RBCs = "Traditional blood"
If you want to know even more information about the specific components of blood, click HERE
So, now that we know the components of blood within a tube, we can understand what an ESR means. The name very eloquently describes this simple blood test: erythrocyte (red blood cell) sedimentation (falling towards the bottom) rate (which is within a specific time frame). So, the ESR is the rate at which these red blood cells fall towards the bottom of the test tube measured in mm/hr.
So quick summary - one of the major components of whole blood, RBCs, are timed in an hour to see how far they fall to the bottom of the test tube (measured in mm)
Why Is This Test Used?
ESR is used in the diagnosis and management of a wide variety of different diseases including chronic inflammatory diseases such as rheumatoid arthritis and infections such as pneumonia.
There are specific physiological and pathological conditions that can raise or lower the ESR. I won't go into details on why as it would be fairly confusing
I think it's important to mention that ESR can be increased under normal circumstances such as individuals who are pregnant, menstruating, or elderly. It can also be increased in individuals taking specific medication such as Vitamin A and OCPs.
What Is The Normal Range?
Men
age < 50 = < 15 mm/hr
age > 50 = < 20 mm/hr
Women
age < 50 = < 20 mm/hr
age> 50 = < 30 mm/hr
If your ESR value is elevated it could mean that you have some sort of inflammatory process occurring in your body. If you are concerned about your ESR, please consult your local health care provider
