Hypoxia and Medicine

Which of the following represents a feature that would allow humans to get enough oxygen at high altitudes?

(1) a decrease in the breathing rate, combined with a decrease in lung size (2) a reduction in the amount of hemoglobin in the blood (3) an increase in the amount of hemoglobin in the blood (4) a decrease in the area of the gas exchange surface inside the lung

Public Comments

1. 3
2. number 3
3. That is more of a medical question, and I do not think you will get too many accurate, or knowledgeable answers here.
4. You want to get the hemoglobin level up. Too little caused by less oxygen can cause one to get sick and pass out. They can die. It happens every year on several high mountains.