Re: What is Sedimentatin Rate

Dear Eva,

ESR stands for erythrocyte sedimentation rate. Basically it is the time it 
takes red blood cells (erythrocytes) to settle out of blood plasma. ESR 
increases if the number (or concentration) of proteins in your blood 
plasma goes up, thus increasing the viscosity. The more viscous a liquid 
(plasma) the slower a cell (erythrocyte) takes to settle. Certain disease 
states produce higher amounts of plasma proteins. There are many reasons 
that bring about a rise in ESR, cancer is one possibility but so are long-
term bacterial or viral infections as well as rheumatic diseases. 

ESR is a valuable screening tool but it is not specifically diagnostic, 
because there are so many things that can cause such a general change in 
blood plasma. More tests, specific to each of the possible explanations 
for a rise in ESR will undoubtedly have to be undertaken before a 
diagnosis can be made.