What should you know about Mont Blanc altitude sickness?

Altitude sickness is a group of problems caused by rapid ascent to higher ground. Early symptoms can include headache, nausea, dizziness, unusual tiredness, poor sleep and reduced appetite. Headache and Nausea can also have ordinary causes, so the timing after ascent and whether symptoms improve at a lower altitude matter.

Fitness does not guarantee protection. Previous altitude illness, a rapid itinerary, dehydration, cold, exertion and respiratory illness may increase concern. More serious illness can affect the brain or lungs, causing confusion, poor coordination, breathlessness at rest, a persistent cough or frothy sputum.

Arrange a Travel Health Consultation before the trip to review the route, previous altitude problems, medicines and medical conditions. Build rest and acclimatisation into the itinerary, ascend gradually, drink regularly without forcing fluids, eat as tolerated and avoid alcohol while adapting. Tell a guide early about symptoms. Stop ascending while symptoms are present; rest at the same altitude only if symptoms are mild and improving.

Descend immediately and seek emergency help for confusion, difficulty walking, fainting, breathlessness at rest, blue lips, severe weakness or a worsening headache. Do not leave a confused or very unwell climber alone. Oxygen or other treatment may be needed under medical supervision, but these should not delay descent when serious symptoms appear.

Ask how your route affects acclimatisation, which symptoms require descent, whether any prescribed medicine is appropriate, and how your existing conditions or medicines could alter the plan.