Which of the following is NOT a type of hypoxia?

• A. Hypemic
• B. Hypoxic
• C. Histotoxic
• D. Hyperoxic

Answer: (D)

Hypoxia means tissues aren’t getting enough oxygen, but there are different ways this can happen. If the blood’s oxygen-carrying capacity is reduced—like in anemia or when carbon monoxide binds to hemoglobin—there isn’t enough oxygen being delivered to the tissues, which is hypemic hypoxia. If the problem is that not enough oxygen is reaching the blood from the lungs or the inspired oxygen is low, that’s hypoxic hypoxia. If the body’s cells can’t use the oxygen available, due to a toxin blocking cellular respiration, that’s histotoxic hypoxia. Hyperoxic, on the other hand, is an excess of oxygen, the opposite of hypoxia, and while high oxygen can be used therapeutically, it isn’t a type of hypoxia.