Which type of hypoxia is caused by reduced oxygen-carrying capacity of the blood?

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

Answer: (B)

The key idea here is how much oxygen the blood can actually carry to tissues. Oxygen delivery depends on the amount and function of hemoglobin in the blood. If something reduces this carrying capacity—such as fewer red blood cells or hemoglobin that can’t bind oxygen effectively—the blood’s oxygen content falls. Even if the lungs are oxygenating the blood normally, the tissues don’t get enough oxygen because the blood can’t transport it efficiently. This situation is known as hypemic hypoxia.

Examples include anemia, where hemoglobin is deficient, or conditions where hemoglobin doesn’t function properly (like carbon monoxide binding to hemoglobin or methemoglobinemia). By contrast, hypoxic hypoxia arises from insufficient oxygen entering the blood, histotoxic hypoxia from cells being unable to use oxygen, and stagnant hypoxia from poor blood flow. Here, the distinguishing factor is the blood’s reduced capacity to carry oxygen.