Sedimentation Rate (Sed Rate)

The sedimentation rate (sed rate) blood test measures how quickly red blood cells (erythrocytes) settle in a test tube in one hour. The more red cells that fall to the bottom of the test tube in one hour, the higher the sed rate.

When Reference inflammation Opens New Window is present in the body, certain Reference proteins Opens New Window cause red blood cells to stick together and fall more quickly than normal to the bottom of the tube. These proteins are produced by the liver and the Reference immune system Opens New Window under many abnormal conditions, such as an infection, an Reference autoimmune disease Opens New Window, or cancer.

There are many possible causes of a high sedimentation rate. For this reason, a sed rate is done with other tests to confirm a diagnosis. After a diagnosis has been made, a sed rate can be done to help check on the disease or see how well treatment is working.

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