Does hydration prevent altitude sickness?
At present there is very little data to show that hydration per se influences susceptibility to altitude sickness. However it is a bad idea to be dehydrated in the mountains as symptoms of dehydration (headache and fatigue) mimic the symptoms of acute mountain sickness. By the same token you should not overhydrate by drinking fluids excessively as low sodium levels (hyponatremia) may result. If severe, hyponatremia may lead to mental status changes.
