Generally speaking, the basic amount of water needed by human body in a day is about 1500-2000ml. And in summer, because of the hot weather, people sweat more, at least in 2000ml or more, and this amount can also be properly adjusted according to the amount of sweating, and can even reach 2500ml or more. Because water is an important substance to maintain the body’s metabolism, it is involved in a variety of physiological activities of the body, if a long period of water shortage, will lead to an increase in toxins in the body, may also lead to the occurrence of disease. Once the toxins are not discharged from the body in a timely manner, it may increase the chances of urinary stones and infections. However, you should not drink too much water, if you drink too much water a day, it will also increase the burden on the kidneys and may cause symptoms such as puffy eyelids.