Terminate ascent and/or descend 
Descend to lower altitude of 300-500m (1000-3000ft) OR acclimatize for 12-36hr at same altitude
Acetazolamide
Mechanism: speeds acclimatization by promoting bicarb diuresis
Indications:
History of altitude illness
Abrupt ascent to >9800ft<unk>  requiring treatment
Bothersome periodic breathing during sleep
125-250mg PO BID until symptoms resolve
Side-effects
Allergic reaction (if patient allergic to sulfa), paresthesias, polyuria, carbonated beverages taste bitter
Can also worsen dehydration by promoting bicarb diuresis
Symptomatic treatment as necessary with analgesics (NSAIDs) and antiemetics (ondansetron)
Sleep-agents
Benzos are only safe if given in conjunction with acetazolamide
Nonbenzodiazepines are safe (zolpidem, diphenhydramine)
Descend to lower altitude of 300-500m (1000-3000ft) OR acclimatize for 12-36hr at same altitude
Mechanism: speeds acclimatization by promoting bicarb diuresis
Indications:
History of altitude illness
Abrupt ascent to >9800ft<unk>  requiring treatment
Bothersome periodic breathing during sleep
125-250mg PO BID until symptoms resolve
Side-effects
Allergic reaction (if patient allergic to sulfa), paresthesias, polyuria, carbonated beverages taste bitter
Can also worsen dehydration by promoting bicarb diuresis
History of altitude illness<unk>  requiring treatment
Bothersome periodic breathing during sleep
Allergic reaction (if patient allergic to sulfa), paresthesias, polyuria, carbonated beverages taste bitter
Can also worsen dehydration by promoting bicarb diuresis
Benzos are only safe if given in conjunction with acetazolamide
Nonbenzodiazepines are safe (zolpidem, diphenhydramine)
Immediate descent of 500 m (~ 1500 ft) for worsening symptoms
Low-flow 0.5-1 L/min O2 if available (especially nocturnal administration)
Acetazolamide 250mg PO BID
Dexamethasone 4mg PO q6hr
Symptom-improvement only; unlike acetazolamide does not aid acclimatization
Hyperbaric therapy
Symptom-improvement only; unlike acetazolamide does not aid acclimatization
Acute mountain sickness
Dehydration
Decompression sickness
AMS is not improved by fluid administration alone
Chronic mountain sickness
Body hydration does not influence susceptibility to AMS
High altitude cerebral edema
Exhaustion