Explain Acclimatization - Histotoxic Hypoxia

A compensatory respiratory adjustment at moderately high altitudes is called acclimatization.  If you were to visit places like Leh (Ladakh) you would be told that you would need some time to acclimatize.

At very high altitudes, the alveolar pO₂ may fall to 40 millimeters of mercury and haemoglobin will be only 75% saturated. At this point, increased ventilation will make a dramatic difference in the amount of oxygen loaded into the blood. At high altitudes, there are not only changes in respiration but also changes in blood and circulation, in kidney.