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Old 11-07-2011
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Hematology Why ESR is low in polycythemia and sickle cell

Do not understand why Sickle cell and polycythemia can cause ESR decreasing.

Any explanation and ideas will be appreciated!
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Old 11-07-2011
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ESR is the column of plasma (in millimeters) that float above the RBCs after one hour standing.

If you have polycythemia (too many RBCs) then there will be no much room for the plasma so the column will be shorter and that makes the ESR decrease. Conversely, in anemia you have higher than normal ESR.

In sickle cell disease, the RBCs are sticky, so they don't easily precipitate down the tube, therefore the plasma column would be shorter (low ESR).

Why ESR is low in polycythemia and sickle cell-esr-tubes.jpg
click image to enlarge

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