Dialysis patients generally have less urine and impaired drainage, so in order to reduce the burden on the heart and avoid excessive weight gain, the amount of water intake needs to be controlled. Drinking water includes all water that enters the body, such as fluids infused and water drunk, diluted rice, drinks, and water from food, such as water from fruits, buns, and vegetables, and also needs to be included, not just plain water that is drunk. The purpose of drinking water is to maintain the patient’s dry weight so that the patient does not gain too much weight per dialysis session, otherwise the heart load is relatively high sometimes inducing heart failure. If the weight gain is more, the amount of ultrafiltration per dialysis is more, which also increases the risk of cardiovascular events. For the safety of the patient, the amount of water drunk needs to be controlled. A relatively simple way of how to drink water is that if the weight weighed before this dialysis is significantly more than after the last dialysis and exceeds a certain range, it suggests that the amount of water intake before is high and needs to be reduced from the previous amount of water. If the weight gain before the next dialysis after drinking water is not so obvious, and the body does not show symptoms of discomfort, the amount of water drunk is appropriate.