Acute mountain sickness - AMS

High urgency
-Very severe
It is a disease that appears in people who are above an altitude of 2500 meters (8200 feet). It is caused by reduced levels of oxygen at high altitudes. Ascending too fast facilitates its onset and neither age nor physical condition provide protection. The most common symptoms are: headache, sleep disturbance, dizziness, fatigue, shortness of breath, vertigo and an inability to walk in a straight line. These appear 6 to 12 hours after reaching the altitude and are typically resolved without treatment. If there is severe shortness of breath, the skin turns a bluish color, there is disorientation, stupor, low level of consciousness and phlegm with blood and pale skin, then more severe complications must be considered: cerebral edema due to altitude and pulmonary edema due to altitude. Diagnosis is clinical. In severe cases, treatment includes descending as soon as possible, administering oxygen and treating the symptoms with diuretics and anti-inflammatory drugs.
Bibliographic references
  1. Scott A Gallagher. High altitude illness: Physiology, risk factors, and general prevention. UpToDate. Abril 2015
  2. Hackett PH. High-altitude medicine. In: Wilderness Medicine, 6th, Auerbach PS (Eds), Elsevier, Philadelphia 2012. p.2
  3. West JB. High Altitude Medicine and Physiology, Hodder Arnold, London 2007.
  4. Wilson MH. The cerebral effects of ascent to high altitudes. Lancet Neurol 2009; 8:175.
  5. Buddha Basnyat. Enfermedad de las altitudes. Harrison. Principios de Medicina Interna, 19e. Capítulo 476e
Author
Dr. Oscar Garcia-Esquirol
Copyright
© TeckelMedical 2026

Symptoms

    Headache


    Morning headaches


    Short of breath


    Constant headache


    Headache at the temples

Pre-hospital care recommendations

Descend below a safe altitude (< 8202 feet).
Maintain a fluid intake of 6 - 8 cups per day.