Avoiding heavy physical activity is helpful. Physical conditioning before ascent does not help. Many patients are young, healthy and energetic. Cerebral edema usually in conjunction with H.A.P.E. is a complication of rapid exposure to very high altitudes seen mainly in mountaineers. Immediate descent and oxygen are recommended to prevent permanent neurological sequelae or death.
Hemorrhages usually resorb and seven to ten days at sea level without impairment of vision.
Rarely, macular hemorrhages affecting vision may occur and require immediate descent to prevent persistent visual defects. The effect is transient, but renal compensation for the primary respiratory alkalosis usually occurs before the effect wears off. Most common side effects are numbness and tingling of lips, fingers and toes. Visual effects may occur. Dehydration may occur if fluid intake is inadequate.