This question is often asked by patients, but it is also one of the worst questions for doctors to answer because there is no uniform standard answer and it is influenced by too many factors. In general, the bypass surgery itself is definitely a blow to the heart in the early postoperative period and can affect the function of the heart. Therefore, we control fluid intake and water intake in the early postoperative period according to various in-hospital monitoring indicators, and even strictly control water intake when the patient feels very thirsty, to reduce the burden on the heart and facilitate postoperative recovery. But after discharge from the hospital, without the various monitoring devices and indicators, even if you go to ask the doctor, the doctor is unlikely to give you a standard answer. Here is a general principle for you: If the heart function is not affected before surgery, and the heart function is normal at the time of discharge review, then you can drink water after discharge without too strict control, and you don’t need to restrict water to the point that you can hardly even swallow and your tongue and lips are dry and cracked. At the three-month review, if the heart function is normal, you can drink water normally, and do not drink a lot of water in a short period of time, just follow the principle of small amount and many times. However, if the heart’s function is significantly impaired due to myocardial infarction before surgery, or if there is a combination of ventricular wall tumor and valve disease, then the amount of water consumed needs to be controlled relatively strictly. After discharge from the hospital, it is important to maintain a somewhat thirsty state in the early stage, slowly and gradually increase the amount of water drunk according to the situation, and strictly grasp the principle of drinking a certain amount of water, in more and more times and in smaller amounts each time. At the same time, you should closely observe whether you have breath-holding, coughing intensified, coughing thin white foamy sputum, if the above phenomenon occurs, it is not just a matter of limiting water intake, it is likely to strengthen the use of diuretics, and once this happens, it is best to go to the hospital for consultation. There is another situation that patients also often ask, saying, “Doctor, I have good water control, I’m not stealing water at all, but I just have less urine, what should I do?” This condition is also related to many factors, such as the patient’s blood pressure, kidney function, heart function status, medications, etc. You can contact your bedside doctor, who may have a better understanding of your condition and can give appropriate solutions. It is more prudent to go to the hospital for further examination if possible. Some patients still do not understand enough about drinking water, and it is true that doctors are not as detailed as they should be. When they came to the hospital, they told the doctor that they did not drink too much water after being discharged from the hospital, that “their children are filial, so they drink three bowls of turtle soup a day to make up for it”, or that “they don’t eat every day, they only drink thin rice”, and that “their mouths are basically not Some of them “do not have time to eat fruits (some fruits are high in water, such as watermelon)” and so on, making doctors laugh and cry. Some patients are not allowed to drink in the ward, but drink raw tap water in the bathroom when they go to the toilet. The purpose of these examples is to show that water control after heart surgery is also one of the main elements of treatment as well as rehabilitation, and should never be ignored. If your mouth is comfortable, your heart may have to suffer, and in the end, it is you who suffers. As a family member, you should also join us and be a qualified supervisor.