Review Of Related Disease (RRD) 5 Practice Exam

Polycythemia is characterized by hematocrit greater than what value?

Greater than 52% Greater than 40% Greater than 60% Greater than 30%

Correct Answer:

Greater than 52%

Explanation:

Hematocrit tells us what fraction of blood is made up of red blood cells. Polycythemia means there’s an actual increase in red cell mass, so the hematocrit climbs above the upper limit of normal. In adults, the upper normal hematocrit is about 52% for men (and lower for many women), so using a value greater than 52% as the threshold best captures when red cell mass is abnormally high. This cutoff is practical because once hematocrit passes that point, blood becomes thicker and the risk of clotting rises. There are different causes of polycythemia (relative, absolute primary like polycythemia vera, or secondary from hypoxia), but the criterion most often used to define it clinically is hematocrit above the upper normal limit around 52%.

Access more questions from this quiz

Continue to Review of Related Disease (RRD) 5 Practice Exam for more practice questions and the full quiz experience.

Access More Questions