What is a sedimentation rate test used for?

A sedimentation rate test, or erythrocyte sedimentation rate (ESR) test, measures how quickly red blood cells settle at the bottom of a test tube containing blood. It is primarily used to detect inflammation in the body, as higher sedimentation rates can indicate the presence of conditions such as infections, autoimmune diseases, or certain cancers. While it is a useful screening tool, the test is not specific to any one disease and is often used in conjunction with other diagnostic tests.