Symptoms of mild altitude sickness include loss of appetite, throbbing headache, nausea, vomiting, sleeplessness or other symptoms.
The cause of the problem is lack of available oxygen. Because there is less oxygen in the air at high elevations, your heart and lungs have to work harder to provide the amount of oxygen needed by your body.
As a result you feel tired, sick and out of sorts. However there are ways to counteract the symptoms.
Top up your water
Dehydration is a common problem at high altitudes. It's important to drink lots of water - at least 1½ quarts a day.
Have a snack
In addition to rest and fluids, you need steady nourishment. Eat small, frequent, carbohydrate-rich meals and snacks.
Take a breath
10 to 12 deep breaths every 4 to 6 minutes can help increase oxygen levels in your blood.
Descend fast
If mild altitude sickness progresses to pulmonary edema (fluid accumulation in the lungs) or other severe disorders, the chance of recovery reduces.
However, descending as little as 500 or 1,000 feet may bring dramatic improvement.