Hypoxia is defined as decreased or insufficient level of oxygen in the tissues. Which choice reflects this definition?

• A. Increased oxygen delivery to tissues
• B. Increased oxygen affinity of hemoglobin
• C. Decreased or insufficient level of oxygen in the tissues
• D. Complete oxygen saturation

Answer: (C)

Hypoxia is a state where tissues are deprived of sufficient oxygen. This definition focuses on the actual oxygen level at the tissue level, which is what determines whether cells can carry out their energy-producing processes. The statement that best reflects this is the one that explicitly says there is a decreased or insufficient level of oxygen in the tissues, since it directly describes the problem—tissue oxygen availability.

Increasing oxygen delivery to tissues would reduce or prevent hypoxia, so that option describes the opposite of the condition. A change in hemoglobin’s oxygen affinity affects how readily hemoglobin picks up or releases oxygen, which influences delivery and unloading but does not by itself define tissue oxygen levels. Complete oxygen saturation means the blood is fully oxygenated, which does not describe a lack of oxygen in tissues.