Did you know that a lots of people think that because there is less oxygen at high altitudes, you are more likely to get tipsy on just a few drinks? Well, that is not the case. It is actually a huge misconception that it is easier to get drunk in the mountains. But there's another possible pitfall: Alcohol can raise your risk of altitude sickness.
When you are in the mountains, your body naturally compensates for the reduced oxygen by speeding up your breathing. Alcohol slows your breath rate, cutting your oxygen supply further, which can aggravate symptoms such as dizziness, headaches, nausea and sleep disturbances. If you don't want to abstain completely, keep in mind that fifty grams of alcohol (the equivalent of two margaritas) is enough to slow your breath rate. One glass of wine won't make any difference, but two or three glasses might.
If you want to avoid the risk of altitude sickness altogether, try to ascend gradually. So, if you are going to much higher altitude than you're used to, give your body time to adjust and spend a night at 5,000 feet before going any higher.