Erythrocyte sedimentation rate (ESR) is a medical term that refers to a laboratory test used to measure the rate at which red blood cells (erythrocytes) settle to the bottom of a tube in a specified amount of time. This measurement is an indirect marker of inflammation in the body and is therefore commonly used in diagnosing and monitoring various medical conditions.
During the ESR test, a blood sample is taken and mixed with an anticoagulant to prevent clotting. The blood is then placed in a long, thin tube and allowed to stand upright for one hour. The ESR is determined by the distance (in millimeters) that the red blood cells have descended in the tube within the specified time.
An elevated ESR may indicate the presence of an underlying inflammatory or infectious condition, such as rheumatoid arthritis, lupus, or an infection. It can also be useful in monitoring the disease activity and response to treatment for these conditions.
It is important to note that the ESR is a nonspecific test, meaning it does not directly identify the specific cause of inflammation. Therefore, it is often used in conjunction with other diagnostic tests to assist in making a comprehensive diagnosis.
The ESR test is relatively simple, cost-effective, and readily available in most clinical settings. However, it should be interpreted in conjunction with the patient's medical history, physical examination, and other laboratory findings to obtain a more accurate diagnosis.
