ESR

The abbreviation for erythrocyte sedimentation rate, which is the rate at which erythrocytes (red blood cells) sink to the bottom of a test tube. The ESR is increased if the level of fibrinogen (a type of protein) in the blood is raised. Fibrinogen is raised in response to a range of illnesses, including inflammation, especially when this is caused by infection or by an autoimmune disease. The ESR is also increased if levels of immunoglobulins are very high, as occurs in multiple myeloma. ESR is therefore useful for helping to diagnose these conditions as well as in monitoring their treatment.