Hypoxia is defined as what?

• A. An excess of carbon dioxide in the bloodstream
• B. A drop in oxygen levels in the blood
• C. Deficiency in the amount of oxygen reaching the tissues
• D. An inability to absorb oxygen in the lungs

Answer: (C)

Hypoxia means tissues aren’t getting enough oxygen to meet their needs. It’s about oxygen delivery to or utilization by the body’s cells, not just the oxygen content in the blood or air. Even if oxygen is present in the lungs and in the blood, problems with circulation, oxygen transport, or cellular use can lead to tissue hypoxia. That’s why the definition focuses on deficient oxygen reaching or being used by the tissues.

This differs from having too much CO2 in the blood (hypercapnia) or from simply having lower oxygen levels in the blood (hypoxemia). It also isn’t about the lungs’ ability to absorb oxygen alone, which could contribute to hypoxia but isn’t the definition by itself.