A high erythrocyte sedimentation, or SED, rate is anything above 22 mm/hr for men or above 29 mm/hr for women, according to Mayo Clinic. An SED test is administered to test for inflammation in the body, and it can be used in diagnosing illnesses such as autoimmune diseases, cancer or infection.
An SED test measures how many red blood cells settle into the bottom of a test tube in a span of 1 hour. The SED rate is proportional to the number of cells that settle, so the higher the SED rate, the more red blood cells that dropped to the bottom of the tube.
