A normal sedimentation rate is less than 15 millimeters per hour for adult men under 50 years old and less than 20 millimeters per hour for men over 50, according to MedlinePlus. Normal range values may vary among different labs.
An erythrocyte sedimentation rate, or ESR, is a test that indirectly measures inflammation and does not test for any specific disorder, Mayo Clinic explains. It can be useful for monitoring of conditions that cause inflammation such as autoimmune disorders, bone infections and certain types of arthritis. It is performed by placing a blood sample in a tall, thin tube where red blood cells gradually settle to the bottom. The distance that the red blood cells fall in one hour is measured as the sedimentation rate. Because inflammation causes red blood cells to clump, these cells fall to the bottom of the tube more quickly, resulting in an increased sedimentation rate.