Why is it important to drink enough water?
Water keeps every part of your body working properly. It helps your body flush wastes and stay at the right temperature. It can help prevent kidney stones and constipation.
You lose water throughout the day—through your breath, sweat, urine, and bowel movements. If you live in a hot climate, you lose even more fluid.
You need to replace this lost fluid to stay healthy. If you don't get enough water, you could become dehydrated. If you get very dehydrated, your body no longer has enough fluid to get blood to your organs. This is dangerous.
Do you have to drink only water to stay hydrated?
All liquids help you stay hydrated. Water is usually the best choice, because it's free (if you're drinking tap water) and has no sugar or calories. But most healthy people can get enough fluid through the beverages they consume every day. These can include water, fruit juices, coffee, sodas, iced tea, and other drinks.
Experts say that it's not true that beverages that have caffeine—such as coffee, tea, and cola drinks—always dehydrate you. Healthy people who consume moderate amounts of caffeine don't lose more fluid than people who don't have any caffeine.1 A moderate amount of caffeine is about 200 to 300 milligrams a day. That's about two to four 8-ounce cups of coffee.
You also get water through food. Some fruits and vegetables contain a lot of water, such as watermelon and lettuce.
How much water do you need to drink every day?
A common recommendation is to drink six or eight 8-ounce glasses of water or other fluid every day. But some adults may need more or less, depending on how healthy they are, how much they exercise, and how hot and dry the climate is.
You may sometimes need to drink more water than usual if you: