How do you differentiate high-altitude pulmonary edema from high-altitude cerebral edema?

• A. HAPE presents with dyspnea, hypoxia, and clear lungs.
• B. HACE presents with confusion and ataxia.
• C. HAPE presents with dyspnea, hypoxia, and clear lungs; HACE presents with confusion, ataxia, and altered mental status.
• D. HACE presents with chest pain and coughing.

Answer: (C)

High-altitude edema syndromes show distinct patterns based on where the fluid accumulates. Fluid in the lungs (pulmonary edema) causes trouble breathing and low oxygen levels, which characteristically present as dyspnea and hypoxemia; the lungs may appear surprisingly clear on exam, especially early on, because the edema is in the interstitium and air spaces rather than producing obvious chest sounds. In contrast, brain swelling from high-altitude cerebral edema drives neurologic changes—confusion, problems with coordination such as ataxia, and altered mental status.

So, pairing dyspnea and hypoxia with clear lungs points to pulmonary involvement, while confusion, ataxia, and altered mental status point to cerebral involvement. That combination is what distinguishes the two conditions, making the described statement the best fit. Chest pain and coughing aren’t defining features of high-altitude cerebral edema, and mixing neurologic signs with primary pulmonary signs wouldn’t correctly separate the two.