Adults need to drink 2500-3500mL of water per day, but the amount of water adults drink depends on the presence of disease and the specific situation. If an adult suffers from chronic cardiac or renal insufficiency, the amount of water needed to drink is reduced by 500-1000 mL per day from the above, as excessive water intake can cause an increase in the load on the heart and kidneys, leading to secondary edema. However, for patients with aura heat stroke or acute gastroenteritis in summer, with excessive vomiting or diarrhea and certain symptoms of dehydration, they need to drink more than 1000-1500mL on top of the amount of water they just drank in order to ensure the body’s ionic balance and not to have ionic disorders.