What does stagnant hypoxia refer to?

• A. Hypoxia due to dehydration
• B. A type of hypoxia that results when the oxygen-rich blood in the lungs is not moving to the tissues that need it.
• C. Hypoxia due to low atmospheric oxygen
• D. Hypoxia caused by anemia.

Answer: (B)

Stagnant hypoxia happens when oxygenated blood isn’t being delivered to the body's tissues due to poor circulation. Even though the lungs are keeping the blood oxygenated, the flow to where it’s needed is too slow or obstructed, so tissues don’t receive enough oxygen. This is why the description—oxygen-rich blood in the lungs not moving to the tissues that need it—fits. It can occur with conditions that slow or pool blood, like heart failure, shock, or high G-forces in flight. Other forms involve not enough oxygen in the environment (hypoxic hypoxia) or reduced oxygen-carrying capacity of the blood (hypemic hypoxia, such as anemia), rather than a circulation delivery problem.