Which factors may affect hematocrit values?

Hematocrit values reflect the proportion of blood volume that is occupied by red blood cells and can be influenced by several physiological and environmental factors. Hydration status plays a significant role; dehydration can lead to a higher hematocrit because of a lower plasma volume, while over-hydration can dilute the red blood cells, leading to a lower hematocrit.

Living at high altitude also impacts hematocrit values, as the body responds to lower oxygen levels by increasing red blood cell production, thus elevating hematocrit to enhance oxygen transport in the blood.

Additionally, an extremely high white blood cell (WBC) count can affect hematocrit readings due to the overall blood composition. An elevated WBC count can indicate an underlying condition that triggers inflammation or infection, potentially influencing fluid shifts and hemoconcentration.

Since each of these factors—hydration status, altitude adaptation, and elevated WBC count—individually affects hematocrit values, the answer that encompasses all these contributing elements is the most comprehensive and accurate choice.