<prompt> True about ascent to high altitude:Respiratory acidosisPolycythemia due to dehydrationAcute mountain sickness stas to develop on 7th day of ascentAcetazolamide may be given prophylactically  <response>: Respiratory alkalosis occurs Polycythemia is due to increased erythropoietin Acute mountain sickness develops 8-24 hr after arrival at altitude and lasts 4-8 days. Acute altitude illness: 3 forms Acute mountain sickness AMS The pathophysiology of AMS is not well understood. The essential factor responsible for this condition is hypoxemia High altitude cerebral edema HACE High altitude pulmonary edema HAPE 