What should you know about low altitude sickness?

Early altitude sickness often causes headache, tiredness, light-headedness, nausea, poor sleep, or reduced appetite. Symptoms may begin after several hours at elevation and can become worse during the first period of adjustment. Fitness does not reliably prevent it, and a previous comfortable trip does not guarantee the next one will feel the same.

More serious altitude illness can affect the lungs or brain. Warning changes include breathlessness at rest, a cough, chest tightness, confusion, unusual drowsiness, poor coordination, or difficulty walking normally. These symptoms require urgent action rather than waiting for acclimatisation.

If symptoms start, stop climbing higher, rest, keep warm, and avoid alcohol or sedating medicines. Tell a travelling companion and monitor whether symptoms improve. Descending to a lower elevation is the key response when symptoms are worsening or severe; do not travel upward to find a better view.

Plan gradual ascent, allow rest at intermediate elevations, and discuss prevention with a travel clinician before departure. A Travel Health Consultation can review your itinerary, existing conditions, medicines, and emergency plan.

Get urgent medical help and descend with assistance for breathlessness at rest, confusion, fainting, blue lips, severe headache, repeated vomiting, inability to walk steadily, or a cough producing frothy fluid. Do not leave someone with serious symptoms alone.

Ask which parts of your route create the greatest risk, how to pace the ascent, whether a prescribed medicine is appropriate for your health, what symptoms should trigger descent, and how to arrange emergency help in a remote area.