AltitudeAheadWarning signs and when to descend
The rules that matter most at altitude. Read this before every trip.
Three rules
1. Symptoms at altitude are altitude illness until proven otherwise. Headache, nausea, unusual tiredness or dizziness after gaining altitude should be taken seriously.
2. Don't go higher to sleep with symptoms. Wait at the same altitude until the symptoms are gone, or descend.
3. If symptoms get worse, descend. Don't wait for the next morning if things are deteriorating.
Emergency signs — descend now and get help
• Loss of coordination: stumbling, unable to walk heel-to-toe in a straight line • Confusion, unusual behavior, severe drowsiness or reduced consciousness • Breathlessness at rest, or breathing that doesn't recover with rest • Persistent cough, chest tightness, frothy or blood-stained sputum • Severe headache or vomiting that doesn't settle
These can be signs of HACE or HAPE, which can be fatal. Suspected severe altitude illness requires urgent descent and medical assistance. Even a descent of a few hundred meters can help; keep going down until symptoms clearly improve.
Look after each other
People with HACE often don't notice their own confusion. Watch the people you travel with and speak up. Never leave someone with symptoms alone, and never send them down alone.
Know before you go how you would descend, contact a rescue service and reach medical help on your route.
General information, not medical advice. If you have symptoms at altitude, don't go higher. See the medical disclaimer.
