29/07/2026
Mountain Sickness šļø
A common misconception is that āMountain Sicknessā is a separate disease. Medically, it is not.
The correct umbrella term is High-Altitude Illness (High-Altitude Sickness), which includes four major conditions:
⢠Acute Mountain Sickness (AMS)
⢠Chronic Mountain Sickness (CMS/Mongeās disease)
⢠High-Altitude Pulmonary Edema (HAPE)
⢠High-Altitude Cerebral Edema (HACE)
Acute Mountain Sickness (AMS)
Occurs within hours after rapid ascent, usually above 2,500 m.
Features: Headache (hallmark), nausea, vomiting, dizziness, fatigue, poor sleep.
Treatment: Stop further ascent, rest, acetazolamide, oxygen if required, and descend if symptoms worsen.
Chronic Mountain Sickness (CMS/Mongeās disease)
Occurs after months to years of living at high altitude.
Features: Excessive polycythemia, cyanosis, breathlessness, fatigue, and pulmonary hypertension.
Treatment: Descent to lower altitude, oxygen therapy, and venesection in selected cases.
High-Altitude Pulmonary Edema (HAPE)
A life-threatening emergency caused by fluid accumulation in the lungs.
Features: Severe breathlessness, cough, pink frothy sputum, crackles, and hypoxemia.
Treatment: Immediate descent, high-flow oxygen, nifedipine, and a portable hyperbaric bag if descent is delayed.
High-Altitude Cerebral Edema (HACE)
A life-threatening emergency due to brain swelling, often developing from severe AMS.
Features: Severe headache, ataxia (hallmark), confusion, altered consciousness, and coma.
Treatment: Immediate descent, high-flow oxygen, dexamethasone, and a portable hyperbaric bag if required.
High-Yield Pearls
⢠High-Altitude Illness is the umbrella term.
⢠AMS, CMS, HAPE, and HACE are its four major forms.
⢠HAPE and HACE are medical emergencies.
⢠āMountain sicknessā is not a separate fifth disease. It is a term used in Acute Mountain Sickness and Chronic Mountain Sickness, while the overall classification is High-Altitude Illness.