HAPE and HACE are the two severe, life-threatening forms of altitude illness, both medical emergencies requiring immediate descent. HAPE (pulmonary edema) is fluid in the lungs, causing breathlessness and a cough; HACE (cerebral edema) is brain swelling, causing confusion and loss of coordination. They can occur together.
| Aspect | HAPE | HACE |
|---|---|---|
| Affects | The lungs | The brain |
| Key symptoms | Breathlessness, cough, fatigue | Confusion, ataxia, altered consciousness |
| Hallmark sign | Breathless at rest, frothy cough | Can't walk heel-to-toe |
| Severity | Life-threatening | Life-threatening |
| Response | Immediate descent + care | Immediate descent + care |
It's likely HAPE if…
- Breathlessness out of proportion to effort
- A cough, sometimes frothy or pink
- Chest tightness, worse at night
It's likely HACE if…
- Confusion or strange behavior
- Stumbling, loss of coordination
- Severe headache and drowsiness
Verdict
Frequently asked questions
What's the difference between HAPE and HACE?
HAPE (high-altitude pulmonary edema) is fluid in the lungs, causing breathlessness, cough, and fatigue; HACE (high-altitude cerebral edema) is swelling of the brain, causing confusion, loss of coordination, and altered consciousness. Both are severe altitude illnesses and emergencies.
Can you have both HAPE and HACE?
Yes — they can occur together, and both often follow untreated acute mountain sickness. Having one raises concern for the other. Either, or both, means descending immediately and seeking emergency care.
What's the first response to HAPE or HACE?
Immediate descent to lower altitude is the single most important action for both. Supplemental oxygen, a portable hyperbaric (Gamow) bag, and certain medications can help and buy time, but they don't replace descent. Treat both as life-threatening emergencies.
Related: HAPE · HACE · Altitude sickness · Acclimatization