Which type of hypoxia is caused by a reduction in the oxygen carrying capacity of the blood?

Which type of hypoxia is caused by a reduction in the oxygen carrying capacity of the blood?

• A. Hypoxic Hypoxia
• B. Hypemic Hypoxia
• C. Stagnant Hypoxia
• D. Histotoxic Hypoxia

Answer: (B)

This item emphasizes how oxygen delivery to tissues is limited by the blood’s ability to carry oxygen. When the amount of functional hemoglobin or its oxygen-carrying capacity is reduced, the blood can’t transport enough O2 to meet tissue needs, even if lung oxygen tension is normal. That scenario is hypemic hypoxia, seen in conditions like anemia or when hemoglobin is bound by carbon monoxide or altered by methemoglobinemia, which lowers the effective carrying capacity. In contrast, hypoxic hypoxia arises from low arterial oxygen tension (low PaO2) reducing the amount of O2 available for transfer, stagnant hypoxia from poor circulation or pooling that limits delivery despite normal oxygen content, and histotoxic hypoxia from tissues being unable to utilize oxygen due to metabolic poisons. The question’s cause—reduction in the blood’s oxygen carrying capacity—maps directly to hypemic hypoxia.

This item emphasizes how oxygen delivery to tissues is limited by the blood’s ability to carry oxygen. When the amount of functional hemoglobin or its oxygen-carrying capacity is reduced, the blood can’t transport enough O2 to meet tissue needs, even if lung oxygen tension is normal. That scenario is hypemic hypoxia, seen in conditions like anemia or when hemoglobin is bound by carbon monoxide or altered by methemoglobinemia, which lowers the effective carrying capacity.

In contrast, hypoxic hypoxia arises from low arterial oxygen tension (low PaO2) reducing the amount of O2 available for transfer, stagnant hypoxia from poor circulation or pooling that limits delivery despite normal oxygen content, and histotoxic hypoxia from tissues being unable to utilize oxygen due to metabolic poisons. The question’s cause—reduction in the blood’s oxygen carrying capacity—maps directly to hypemic hypoxia.