Altitude sickness in travellers

Acute mountain sickness commonly presents with headache alongside nausea, dizziness, fatigue, reduced appetite, or disturbed sleep after gaining elevation. Fitness does not prevent it, and a traveller may become ill even after previous trips without problems. The pattern of ascent and sleeping elevation matters more than the height reached briefly during the day.

More severe altitude illness can affect the brain or lungs. Poor balance, altered thinking, unusual sleepiness, and breathlessness at rest are not features to walk off or cover with pain medicine.

Build a route that gains sleeping elevation gradually and includes time for acclimatisation. Avoid racing to match a fixed itinerary when someone feels unwell. If mild symptoms begin, stop ascent, rest at the same elevation, avoid alcohol and sedatives, and tell a companion or guide. Never send an affected traveller down alone.

Descend when symptoms worsen, fail to improve with rest, or interfere with normal activity. Travel insurance contacts, local rescue arrangements, communication options, and the nearest suitable medical facility should be identified before entering a remote area. Prescription prevention may be appropriate for some itineraries after an individual clinical discussion.

Begin immediate descent and seek emergency assistance for confusion, loss of coordination, difficulty walking, severe drowsiness, breathlessness while resting, chest tightness, blue or grey lips, a wet cough, collapse, or rapid deterioration. Limit exertion and use emergency oxygen if trained help makes it available. Bad weather or a scheduled summit attempt should never take priority over these signs.

Share the route, highest overnight stops, speed of ascent, access to evacuation, past altitude reactions, regular medicines, and heart or lung conditions. Ask for a clear plan covering prevention, what to carry, when to stop climbing, and when descent becomes mandatory.