Mountain sickness
Altitude sickness is a common condition that can occur when you climb to a high altitude too quickly. Just because you haven't had it before doesn't mean you won't develop it on another trip.
Symptoms of altitude sickness usually develop between 6 and 24 hours after ascending to high altitude and can be similar to a bad hangover.
Altitude sickness can be treated by descending to a lower altitude, oxygen treatment, and different types of medication. If you have symptoms of mild altitude sickness, you shouldn't go any higher for at least 24 to 48 hours.
Altitude sickness can cause potentially life-threatening conditions that affect the brain or lungs.If HACE isn't treated immediately, it's likely it will be fatal. Immediate descent to a lower altitude is necessary to prevent this.
Proper acclimatisation to altitudes of 2,500m (just over 8,200 feet) or above is the best way to prevent altitude sickness. Ascending slowly will give your body time to adapt to the change in altitude.
Jessica Mathur, a GP from London, was surprised when she became ill with altitude sickness during a holiday in Peru. I found it difficult to believe that I had altitude sickness. I just didn't expect it would happen to me.
After years of mountain climbing, David Hillebrandt learnt how to deal with his altitude sickness. "It's still as bad as it was 30 years ago. The only difference is that now I know how to deal with it."