What causes hypemic hypoxia?

Hypemic hypoxia occurs specifically when there is a reduced ability of the blood to carry oxygen. This typically happens due to a lack of sufficient oxygen-carrier hemoglobin in the blood. Conditions that can lead to this include anemia, where there is a reduced number of red blood cells, or carbon monoxide poisoning, where hemoglobin is bound to carbon monoxide instead of oxygen.

In contrast, the other options describe different types of hypoxia. A lack of oxygen due to altitude causes hypoxic hypoxia since the overall partial pressure of oxygen in the environment is lower. The inability of hemoglobin to utilize available oxygen refers to histotoxic hypoxia, which often involves poisons that interfere with the cellular processes using oxygen. Malfunction of circulation can lead to stagnant hypoxia, where blood flow is insufficient to deliver oxygen to tissues despite adequate levels in the blood. Understanding these distinctions highlights why insufficient hemoglobin is central to hypemic hypoxia.