High altitudes can make dehydration more likely. Water evaporates more quickly from the skin and lungs at high altitude, so your fluid loss may be faster, but you may not notice how much fluid you lose through perspiration, as it dries so quickly. Drinking plenty of water is important to prevent dehydration, but it is also important to maintain your sodium levels, which can be diluted when you drink more water. As you sweat, you also lose salts from your body, so it is important to ensure that both your water and sodium levels are maintained. Rehydration salts and electrolyte drinks are recommended for this. It is also important to avoid caffeine and alcohol as they can contribute to dehydration. Dehydration can also mask other health problems, therefore it is important to stay hydrated.