Generally speaking, for adults, the most appropriate amount of water should be 1500-2000mL per day. However, there are some exceptions for adults. For example, if an adult has endocrine or metabolic disorders, if the endocrine state is hyperactive, such as hyperthyroidism, then the daily water intake should be increased by 500-800mL to meet the needs of a high basal metabolic rate. However, if the endocrine basal metabolic rate is low, such as hypothyroidism or adrenocortical insufficiency, such people should reduce their daily water intake by about 800mL. In addition, in patients with relatively severe dehydration, such as heat stroke in summer, they should supplement their drinking water with more than 1500mL of drinking water per day to avoid dehydration.