Altitude Illness - Pulmonary Syndromes Clinical Presentation

Updated: Dec 11, 2017
  • Author: N Stuart Harris, MD, MFA, FACEP; Chief Editor: Joe Alcock, MD, MS  more...
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HAPE generally occurs 2-4 days after ascent to high altitude, often worsening at night. Decreased exercise performance is the earliest symptom, usually associated with a dry cough. The early course is subtle; as the illness progresses, the cough worsens and becomes productive; dyspnea can be severe, tachypnea and tachycardia develop, and drowsiness or other CNS symptoms may develop. Chest radiographs characteristically show patchy unilateral or bilateral fluffy infiltrates and a normal cardiac silhouette. The presence of a low-grade fever has led to misdiagnosis as pneumonia and to subsequent deaths.

HAPE varies in severity from mild to immediately life-threatening. It can be fatal within a few hours, and it is the most common cause of death related to high altitude. Differential diagnosis is sometimes problematic, but HAPE improves dramatically with descent or oxygen, whereas other diagnoses do not; these should be pursued in patients who do not fit this pattern.

The Lake Louise Consensus definition of HAPE requires at least 2 of the following symptoms (in the context of a recent elevation gain):

  • Weakness or decreased exercise
  • Cough
  • Dyspnea at rest
  • Chest tightness or congestion

Physical Examination

In addition to two symptoms, the Lake Louise Consensus definition of HAPE requires at least two of the following signs [17] :

  • Rales or wheezing in at least one lung field
  • Central cyanosis or arterial oxygen desaturation relative to altitude
  • Tachycardia
  • Tachypnea

Fever and orthopnea are commonly present in HAPE; pink/frothy sputum is a late finding in severe HAPE.



Secondary pulmonary infections may occur. Note that a productive cough while recovering from HAPE is common. Use Gram stain or culture to evaluate for cases requiring antibiotic therapy.