Summary of the major high-altitude illnesses
| Disease | Primary symptoms | Prevention | Treatment |
| AMS | Headache plus one or more of the following: lightheadedness; nausea; vomiting; lethargy; poor sleep | Slow ascent; avoid overexertion; acetazolamide 125 mg or 250 mg b.i.d. or dexamethasone 2 mg q.i.d. | Stop ascending; non-narcotic pain relievers for headache; antiemetics; acetazolamide 250 mg b.i.d. |
| HACE | Pre-existing symptoms of AMS or HAPE; ataxia; altered mental status; coma | Slow ascent; avoid overexertion; acetazolamide 125 mg or 250 mg b.i.d. or dexamethasone 2 mg q.i.d. | Descend until symptoms resolve; supplemental oxygen; portable hyperbaric chamber; dexamethasone 1×8 mg then 4 mg q.i.d. |
| HAPE | Mild: decreased exercise performance and dry cough; severe: dyspnoea with minimal exertion or at rest; cough with pink, frothy sputum; cyanosis | Slow ascent; avoid overexertion; nifedipine SR 20 mg b.i.d. and/or salmeterol 125 μg b.i.d. | Descend until symptoms resolve and avoid overexertion on descent; supplemental oxygen; portable hyperbaric chamber; short-acting nifedipine 10 mg then nifedipine SR 30 mg b.i.d. |
| Subacute Mountain Sickness | Dyspnoea; exercise angina; cough; ascites; peripheral oedema; cardiomegaly; polycythaemia | No documented strategies for prevention | Diuretic therapy; descent to lower elevation |
| Chronic Mountain Sickness | |||
| Polycythaemic form | Headache; lethargy; confusion; mucosal congestion; cyanosis; clubbing | No documented strategies for prevention | Descent to lower elevation; alternatives to descent include periodic phlebotomy and respiratory stimulants |
| Isolated right heart failure | Headache; dyspnoea; cough; oedema; cyanosis; tachycardia; hepatomegaly | Descent to lower elevation |
AMS: acute mountain sickness; HACE: high-altitude cerebral oedema; HAPE: high-altitude pulmonary oedema.