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What is a sedimentation rate?
A sedimentation rate is common blood test that is used to detect and monitor inflammation in the body. The sedimentation rate is also called the erythrocyte sedimentation rate because it is a measure of the red blood cells (erythrocytes) sedimenting in a tube over a given period of time. Sedimentation rate is often abbreviated as "sed rate" or ESR.
How is a sedimentation rate performed?
A sedimentation rate is performed by measuring the rate at which red blood cells (RBCs) settle in a test tube. The RBCs become sediment in the bottom of the test tube over time, leaving the blood serum visible above. The classic sedimentation rate is simply how far the top of the RBC layer has fallen (in millimeters) in one hour. The sedimentation rate will be higher in the presence of increased inflammation.
What is the normal sedimentation rate?
The normal sedimentation rate (Westergren method) for males is 0-15 millimeters per hour, females is 0-20 millimeters per hour. The sedimentation rate may normally be slightly higher in the elderly.
Medically reviewed by a Board Certified Family Practice Physician
National Institutes of Health