Hi. WSR means Westegren Sedimentation Rate also referred to as ESR. The sedimentation rate (sed rate) measures how quickly red blood cells (erythrocytes) settle in a test tube. The more red cells that fall to the bottom in one hour, the higher the sed rate.
It is usually drawn to help determine whether a condition causing inflammation is present and/or to monitor the response to treatment of some conditions (such as infection or some autoimmune diseases).
When inflammation (such as arthritis, fibromyalgia, infection, etc)is present, certain proteins cause red blood cells to stick together and fall more quickly than normal to the bottom of the tube. These proteins are produced by the liver and the immune system under many abnormal conditions. There are many possible causes of an elevated sedimentation rate. For this reason, a sed rate is done with other tests to confirm a diagnosis.
Hope this helps