Diseases

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.

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. Although this test measures a general state of inflammation, it is not specific to what causes the inflammation. It is elevated in inflammatory diseases, including arthritis as well as in autoimmune diseases such as lupus. It can also be elevated due to other conditions such as certain cancers and Grave's disease.

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.

All specialties of medicine can order this simple blood test while evaluating symptoms in order to determine whether or not there is inflammation in the body.

A blood sedimentation rate is tested to detect inflammation in the body. It can also be used to follow the progress of a disease.