system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A 32-year-old high altitude mountaineer is observed to have a hematocrit of 70 percent. Which of the following represents the most likely cause/explanation
assistant
The correct answer is  At high altitude, there can be acute changes and changes due to acclimatization.
Acute mountain sickness

Dyspnoea, dizziness, tiredness, tachycardia, palpitation, nausea, vomiting etc. 
At higher altitudes- pulmonary oedema and cerebral oedema may occur. 

Acclimatization changes

Hyperventilation leading to respiratory alkalosis 
Increased 2,3DPG- Hb-O2 dissociation curve shifts to right. 
Increased erythropoietin leading to absolute polycythemia with increased red cell mass. 
Increased renal excretion of bicarbonate 
Increased tissue vascularity 
Increased oxidative metabolism 
Increased diffusion capacity of the lung​
Increased myoglobin