Hypoxic hypoxia is defined as which condition?

Hypoxic hypoxia is defined as which condition?

• A. Not enough CO2 in air
• B. Excess oxygen in lungs
• C. Oxygen toxicity
• D. Not enough O2 in air

Answer: (D)

Hypoxic hypoxia happens when there isn’t enough oxygen in the air to keep the blood adequately oxygenated. In flight, as altitude increases, the partial pressure of oxygen in the surrounding air drops, so the lungs can’t load as much O2 onto the blood. Even with normal breathing mechanics, arterial O2 levels fall and tissues don’t get the oxygen they need. This is different from situations caused by too little CO2 in the air (which affects respiration but not the basic oxygen content of the blood), or by oxygen toxicity (too much O2 causing tissue damage), or from issues where the air’s O2 is actually sufficient but other factors prevent delivery. So not enough O2 in the air is the defining condition here.

Hypoxic hypoxia happens when there isn’t enough oxygen in the air to keep the blood adequately oxygenated. In flight, as altitude increases, the partial pressure of oxygen in the surrounding air drops, so the lungs can’t load as much O2 onto the blood. Even with normal breathing mechanics, arterial O2 levels fall and tissues don’t get the oxygen they need. This is different from situations caused by too little CO2 in the air (which affects respiration but not the basic oxygen content of the blood), or by oxygen toxicity (too much O2 causing tissue damage), or from issues where the air’s O2 is actually sufficient but other factors prevent delivery. So not enough O2 in the air is the defining condition here.