As a certified SOB (Survivor of Bolivia), as well as Peru and Ecuador, for many years, please let me add a few comments. The links posted by Tiger4x4RV are essential reading.
-- Diamox works well for many people. Not me, but for most folks it does make a difference. Dramamine can also be help in suppressing vomiting. This is only a treatment of the symptoms, but in general, it is easier to control vomiting if you don't start.
-- Analgesics help with headaches for the first three or four days. (You are going to get them; why suffer?)
-- The most dangerous sign is a persistent, non-productive or "dry" cough. After about six hours this is almost certainly a sign of pulmonary edema and you need to get on inhaled oxygen fast. This one can kill you quickly.
-- Hydrate! The old mountaineer's rule is that your urine should be "gin clear." (Good luck, but you get the idea.)
People with Sickle Cell anemia or Sickle Trait are at special risk and may not know it. This condition is generally only found in people of African descent, but it is also found in some people of Sicilian descent. (The good news is that people with Sickle Cell can't contract Malaria, but that is another post.)
Final, anecdotal, observation; younger, fitter males suffer more than older females. Can't find any medical data to back this up, but, I have noted it to be true. Be careful.