Altitude sickness
Above roughly 2,500 m, altitude sickness becomes a genuine possibility regardless of fitness. Headache, nausea, poor sleep, and breathlessness are common early signs, and they can progress to conditions that are life-threatening.
Preparing for it: Ascend gradually, build in rest days, drink plenty of water, and descend if symptoms worsen. This is general awareness — talk to a doctor about your own situation.






