The normal daily water intake for adults is 1500-2000ml, but the water intake includes the daily water intake and the water contained in the vegetables and fruits eaten, as well as the soup contained in the food eaten, and the water contained in the functional beverage supplemented daily, which is also included in the daily adult water intake. However, there are exceptions to the daily adult water intake for people with certain underlying diseases, such as those with obvious kidney insufficiency or reduced heart function, who should not drink the above mentioned water, but should reduce 500-800ml above the normal water intake, otherwise it will cause secondary edema and increase the burden on the heart and kidneys. For normal adults who are dehydrated, such as acute gastroenteritis with increased vomiting or diarrhea, it is necessary to supplement more than 500-1000ml of water on top of normal drinking water to avoid ionic disorders.