When might a patient’s RBC count be falsely elevated?

A patient’s red blood cell (RBC) count can be falsely elevated in cases of hemoconcentration. Hemoconcentration occurs when there is a decrease in the volume of plasma in the blood, which can be caused by dehydration, excessive sweating, or certain medical conditions that lead to loss of fluid. In such scenarios, the proportion of red blood cells to plasma increases, resulting in a higher RBC count because the total number of red blood cells remains the same while the plasma volume decreases.

In contrast, situations such as clotted specimens or high reticulocyte counts do not typically lead to a true elevation in the RBC count reading. A clotted specimen may result in inaccuracies in counting the cells but usually would not artificially inflate the count. Similarly, while a high reticulocyte count indicates increased red blood cell production (which could imply anemia or recovery from it), it does not directly cause a false elevation of the overall RBC count measured; rather, it would be an ancillary finding of red blood cell activity. After a blood transfusion, although the RBC count would increase due to the added red blood cells, this is a true increase rather than a false one, reflecting a change in the patient’s actual blood composition.