Key takeaways
- HAPE is a life-threatening buildup of fluid in the lungs from rapid ascent to altitude.
- Hallmark signs: breathlessness at rest, cough (possibly frothy/pink), extreme fatigue, fast heart rate.
- The definitive treatment is immediate descent — even a few hundred meters can be lifesaving.
- Prevent it by ascending gradually and never going higher with symptoms of altitude illness.
Acronym: High-Altitude Pulmonary Edema.
This is general educational information, not medical advice. HAPE is a medical emergency — descend immediately and seek professional help.
What HAPE is
HAPE — high-altitude pulmonary edema — is a severe form of altitude illness in which fluid leaks into the lungs, crippling the body’s ability to take in oxygen. It usually appears above about 2,500 m (8,000 ft) after ascending faster than the body can acclimatize, and it can become fatal within hours.
Warning signs
- Breathlessness at rest — the hallmark, not just on exertion.
- Cough — persistent, sometimes producing frothy or pink sputum.
- Weakness and a sharp drop in exercise tolerance.
- Fast heart rate, chest tightness, and sometimes bluish lips — often worse at night.
At a high camp a climber becomes breathless even lying down and develops a wet cough. The team recognizes HAPE and descends with them immediately through the night — and their condition improves markedly after dropping just a few hundred meters.
Treatment and prevention
The definitive treatment is immediate descent; supplemental oxygen, medication, and a portable hyperbaric chamber can buy time but don’t replace going down. Prevent it by ascending gradually and never climbing higher with symptoms. The brain-swelling counterpart is HACE — see HAPE vs HACE.
The bottom line
HAPE is fluid in the lungs at altitude — a fast-moving, potentially fatal emergency whose warning sign is breathlessness at rest. The lifesaving response is unambiguous: descend immediately, supported by oxygen and medication where available. As with all altitude illness, gradual ascent and never climbing higher with symptoms are the prevention.
Frequently asked questions
What is HAPE?
HAPE, or high-altitude pulmonary edema, is a dangerous condition in which fluid leaks into the lungs at high altitude, blocking oxygen transfer. It's one of the two life-threatening forms of altitude illness (along with HACE) and can be fatal within hours if not treated by descending.
What are the symptoms of HAPE?
Key signs are breathlessness at rest (not just on exertion), a persistent cough that may produce frothy or pink-tinged sputum, marked weakness and reduced exercise tolerance, chest tightness, a rapid heart rate, and sometimes blue-tinged lips or nails. Symptoms often worsen at night. Any of these at altitude is a red flag.
How is HAPE treated?
The single most important treatment is immediate descent — even 300–1,000 m can dramatically improve the victim. Supplemental oxygen and medications (such as nifedipine) and a portable hyperbaric chamber can help buy time, but they do not replace going down. HAPE is a medical emergency requiring urgent evacuation.
Sources
- High-altitude illness — Wilderness Medical Society
- Altitude illness — CDC
- Mountain medicine — UIAA