Erythrocyte sedimentation rate

The erythrocyte sedimentation rate (ESR or sed rate) is the rate at which red blood cells in anticoagulated whole blood descend in a standardized tube over a period of one hour. It is a common hematology test, and is a non-specific measure of inflammation.To perform the test, anticoagulated blood is traditionally placed in an upright tube, known as a Westergren tube, and the distance which the red blood cells fall is measured and reported in mm at the end of one hour.Bone and joint infectionsMyocardial infarction The erythrocyte sedimentation rate (ESR or sed rate) is the rate at which red blood cells in anticoagulated whole blood descend in a standardized tube over a period of one hour. It is a common hematology test, and is a non-specific measure of inflammation.To perform the test, anticoagulated blood is traditionally placed in an upright tube, known as a Westergren tube, and the distance which the red blood cells fall is measured and reported in mm at the end of one hour. Since the introduction of automated analyzers into the clinical laboratory, the ESR test has been automatically performed. The ESR is governed by the balance between pro-sedimentation factors, mainly fibrinogen, and those factors resisting sedimentation, namely the negative charge of the erythrocytes (zeta potential). When an inflammatory process is present, the high proportion of fibrinogen in the blood causes red blood cells to stick to each other. The red cells form stacks called rouleaux which settle faster, due to their increased density. Rouleaux formation can also occur in association with some lymphoproliferative disorders in which one or more paraproteins are secreted in high amounts. While abnormal in humans, rouleau formation can be a normal physiological finding in horses, cats, and pigs. The ESR is increased in inflammation, pregnancy, anemia, autoimmune disorders (such as rheumatoid arthritis and lupus), infections, some kidney diseases and some cancers (such as lymphoma and multiple myeloma). The ESR is decreased in polycythemia, hyperviscosity, sickle cell anemia, leukemia, chronic fatigue syndrome, low plasma protein (due to liver or kidney disease) and congestive heart failure. Although increases in immunoglobulins usually increase the ESR, very high levels can reduce it again due to hyperviscosity of the plasma. This is especially likely with IgM-class paraproteins, and to a lesser extent, IgA-class. The basal ESR is slightly higher in females. Erythrocyte sedimentation rate (ESR) is the measure of ability of erythrocytes (red blood cell) to fall through the blood plasma and accumulate together at the base of container in one hour. There are 3 stages in erythrocyte sedimentation: In normal conditions, the red blood cells are negatively charged and therefore repel each other rather than stacking. ESR is also reduced by high blood viscosity, which slows the rate of fall. The rate of erythrocyte sedimentation is affected by both inflammatory and non-inflammatory conditions. In inflammatory conditions, fibrinogen, other clotting proteins, and alpha globulin are positively charged, thus increasing the ESR. ESR begins to rise at 24 to 48 hours after the onset of acute self-limited inflammation, decreases slowly as inflammation resolves, and can take weeks to months to return to normal levels. For ESR values more than 100 mm/hour, investigations should be done to find the underlying causes because there is a 90% probability that cause would be found.