It is a normal phenomenon that the body is particularly tired and uncomfortable after open heart surgery, which may be caused by anesthesia, preoperative fasting, and physical weakness. 1. Anesthesia: It may be caused by anesthesia if the body is particularly tired and uncomfortable even though there is no pain after open-heart surgery. Anesthesia may affect the body to a certain extent during the surgery, and the patient may experience a lack of sensation or movement, and the anesthesia will take a certain amount of time to subside, so the patient will feel fatigued and uncomfortable after the surgery. 2. Pre-operative fasting: the night before the operation is usually fasting, so the body may lack the required energy, although the nutritional supplements will be provided after the operation, they can only maintain the daily needs of life, so the patient will feel tired and uncomfortable after the operation. 3. Weakness: If the patient’s body is weak, he or she may experience weakness, dizziness, malnutrition, etc., so the patient will feel particularly tired and uncomfortable. It is recommended that patients maintain good dietary habits and work and rest habits during the recovery process, which will help the recovery of the disease.