Under normal circumstances, drinking a lot of water at night will not produce significant harm to the kidneys; if there is kidney failure or originally have edema, excessive water consumption, may aggravate the burden on the kidneys, and even hypertension, pulmonary edema and other water overload. Under physiological circumstances the kidneys filter the water in the blood to produce urine stored in the bladder, drinking water can promote the body’s normal metabolism, while reducing the possibility of urinary tract infections. Normal water intake does not harm the kidneys, but if you drink too much water at night, it can cause frequent nighttime awakenings and affect your sleep. However, if you already have kidney failure or edema, it means that the kidney’s ability to excrete water has decreased. Drinking too much water at night, the burden on the kidneys given at this time, may further worsen the condition. Excessive accumulation of water in the body will raise blood pressure, and in severe cases, pulmonary edema can occur, and the latter may have serious consequences. In conclusion, for healthy people, there is no need to worry about drinking water appropriately at night; for patients with edema or decreased kidney drainage capacity, water intake needs to be restricted. It is recommended that any discomfort should go to the hospital in time for active treatment under the guidance of the doctor and improvement of lifestyle.