DefinitionESR stands for erythrocyte sedimentation rate. It is a test that indirectly measures how much inflammation is in the body. However, it rarely leads directly to a specific diagnosis.Alternative NamesErythrocyte sedimentation rate; Sed rate; Sedimentation rateHow the test is performedBlood is drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.Once the blood has been collected, the