Drinking 3 liters of water a day for normal people is usually not harmful to the kidneys, if the patient suffers from kidney disease, drinking 3 liters of water may be harmful to the kidneys. Normal people who drink 3 liters of water a day can excrete it in a short time, and it usually does not affect the kidneys and will not increase the burden of the kidneys. If the patient suffers from kidney diseases such as nephritis, the glomerular filtration function is impaired, edema may occur, etc. At this time, if you drink 3 liters of water may increase the burden on the kidneys and aggravate edema, including puffy eyelids and lower limbs. After drinking water, it is recommended to observe more, if there is swelling of limbs or other discomforts, it is recommended to consult a doctor in time and standardize the treatment in time under the guidance of professional physicians.