Final answer:
In dehydration, the hematocrit or packed cell volume (PCV) would be expected to increase due to a reduction in plasma volume, leading to a higher concentration of erythrocytes in the blood.
Step-by-step explanation:
When a person is dehydrated, you would expect an increase in their hematocrit or packed cell volume (PCV). Dehydration leads to a decrease in plasma volume, which makes the percentage of erythrocytes (red blood cells) in the blood appear higher. As water intake becomes inadequate or water losses are excessive, plasma volume falls and as a result, the hematocrit rises.
This condition could be described as a transient form of polycythemia. In normal circumstances, the hematocrit values fluctuate between 36-50 percent depending on gender and other factors. While dehydration may cause a temporary rise in hematocrit, it is different from polycythemia vera, a rare bone marrow disease that results in the excessive production of erythrocytes.