An Erythrocyte Sedimentation Rate (ESR) is a blood test that measures how quickly red blood cells settle in a test tube. It can show if there is inflammation in the body, which is the immune system's response to injury, infection, and various conditions, including immune system disorders, certain cancers, and blood disorders
. The test is often used to help diagnose or monitor conditions that cause inflammation, such as arthritis, vasculitis, infection, and inflammatory bowel disease
. A high ESR may indicate the presence of an active disease process in the body, but it does not specify the cause of the inflammation, and other tests are usually needed for a diagnosis
. The ESR test is not specific and is typically used in conjunction with other tests to check for infection, an illness that causes inflammation, or some types of cancer
