A bad heart can cause lung disease. The main reason is that cardiac insufficiency can lead to pulmonary stasis as well as decreased resistance. 1. Lung stasis: Blood circulation in the lungs starts from the right ventricle, passes through the pulmonary artery, the capillaries in the lungs, then to the pulmonary veins, and then returns to the left atrium. When the left heart is not functioning properly, the blood that reaches the left heart cannot be pumped out normally, and will gather in the left atrium, and the pressure of the left atrium will increase, and the pressure will be transmitted forward, which will lead to the pressure of the pulmonary blood vessels will also be increased, and the blood will accumulate in the lungs, which will lead to pulmonary edema, and the lack of circulation in the lungs is more prone to induce lung infections, especially in the old and weak patients. 2. Decreased resistance: the heart pumping function of patients with cardiac insufficiency decreases, which leads to varying degrees of ischemia and hypoxia in various tissues and organs, and slow blood circulation, the immune system does not function properly, which leads to a decrease in the body’s resistance, and it is easier to produce a variety of infections, including lung infections. If you are not feeling well, you should consult a doctor in time and follow the doctor’s instructions.