Under normal circumstances, adults can drink 2500-3500mL of water a day. But for some adults belong to the exception, such as chronic heart insufficiency, chronic renal insufficiency patients, the daily water intake should be reduced by 500-1000mL on the basis of the above drinking water, otherwise sodium and water retention will occur, increasing the burden on the heart and kidneys, but also edema and swelling. In the case of low basal metabolic rate diseases, such as hypothyroidism and adrenocortical insufficiency, it is also necessary to reduce the amount of water by 500-1000mL on top of this amount of water drunk, otherwise water and sodium retention will occur, leading to the appearance of pretibial mucous swelling. For patients with obvious liver and kidney insufficiency, the amount of water should also be slightly reduced by 500mL on top of the above mentioned water intake, otherwise it will cause an increased burden on the liver and kidneys.