1. Polycythemia occurs from a. living at high altitudes. b. inadequate intake of iron. c. sickling shape of red blood cells. d. lack of a hormone that controls red blood cell production.

Polycythemia is often a response to living at high altitudes, where the lower oxygen levels prompt the body to produce more red blood cells to improve oxygen delivery. This natural adaptation helps people thrive in oxygen-poor environments, like up in the Andes or the Rockies, where the air is a bit thinner! In addition to altitude, polycythemia can also be triggered by certain medical conditions like chronic obstructive pulmonary disease (COPD) or even tumors that produce excess erythropoietin, the hormone that stimulates red blood cell production. Understanding these triggers can help manage the condition effectively!