The reasons for heart discomfort after exercise are as follows: 1, physiological reasons, for weak and sickly or obese people, lack of exercise is prone to a decline in activity endurance, heart discomfort after exercise is a normal phenomenon. Patients should appropriately increase exercise to enhance resistance, can gradually alleviate the symptoms; 2, pathological reasons, heart failure, coronary heart disease patients with a significant decline in activity tolerance, some patients with minor activities appear cardiac discomfort. Cardiac function grade I is that the patient has no symptoms after activity, cardiac function grade II is that the patient’s daily life is not restricted, cardiac function grade III is that the patient’s daily life is significantly restricted, and cardiac function grade IV patients cannot be active. Therefore, the cause of cardiac discomfort after exercise should be divided into situations. Heart discomfort due to lack of exercise is a normal condition and does not require special treatment. Cardiac discomfort after exercise caused by heart disease should be promptly sought at the hospital for medical help.