Altitude Sickness Treatment

Altitude sickness — most commonly acute mountain sickness (AMS) — happens when the body hasn't acclimatized to lower oxygen levels at elevation, usually above 8,000 feet (2,500 m). Symptoms typically begin 6–24 hours after ascent and include headache, nausea, fatigue, dizziness, and poor sleep. Fitness doesn't predict who gets it; genetics and ascent rate matter more.

The most effective non-drug prevention is gradual ascent: above 3,000 m, sleep no more than 500 m higher per night and take a rest day every 3–4 days. Hydrate well, avoid alcohol for the first 48 hours, and follow the "climb high, sleep low" principle when possible. For rapid-ascent itineraries — trips where these guidelines aren't practical — medication prophylaxis is often added.

Acetazolamide is the most effective preventive medication for AMS — it speeds acclimatization by triggering mild metabolic changes that improve breathing and oxygen delivery. Typical prophylactic dosing is 125 mg twice daily, started 24 hours before ascent and continued for 2 days after reaching maximum altitude. A sulfonamide component and certain medical conditions can be contraindications, so it's worth reviewing before you go.

Severe AMS can progress to high-altitude cerebral edema (HACE) — confusion, ataxia (unsteady walking), severe headache unresponsive to medication — or high-altitude pulmonary edema (HAPE) — shortness of breath at rest, coughing pink or frothy sputum, extreme fatigue. Both are life-threatening and require immediate descent, supplemental oxygen, and emergency evaluation. Do not continue ascending if symptoms worsen.

Acetazolamide commonly causes tingling in the fingers and toes, increased urination, and a metallic taste (especially with carbonated drinks). Dexamethasone — an alternative preventive — can cause insomnia, mood changes, and elevated blood sugar. Nifedipine, used specifically for HAPE prevention in susceptible people, can lower blood pressure. Choice of medication depends on your health history and itinerary.