Normal adult daily water intake is 1500-2000ml, but in summer people are prone to sweating, such as excessive dehydration, or acute gastroenteritis requires rehydration and rehydration, at this time need to add 500-1000ml of drinking water on top of this, that is, the whole day can reach 2500-3000ml of rehydration, such as heat stroke patients or patients with severe diarrhea, dehydration can continue to add 500ml of drinking water, that is, the daily water intake can reach more than 3500ml. If the elderly can reduce the daily water intake, such as excessive drinking water can lead to pulmonary edema or cause hypertension, that is, the elderly can drink 1500ml of water daily.