The appearance of pink foamy sputum is due to the occurrence of pulmonary stasis. Blood from the lungs is returned to the left atrium through the pulmonary veins, and once left heart failure occurs, the venous return from the left atrium will increase in pressure, and thus the symptoms of pulmonary stasis will occur. Therefore, the cause of pink foamy sputum is due to left heart failure. Left heart failure is a relatively common disease, and diuretics can usually be used to relieve the symptoms of left heart failure, so that the pink foamy sputum will be reduced. In addition, it is not possible to sleep in a flat or side-lying position, because the amount of venous blood return will increase, which will increase the burden on the heart and aggravate the symptoms of pulmonary stasis. The upper half of the body should be elevated to reduce the amount of venous return, so that the pressure on the left heart will be reduced, and the symptoms of pulmonary stasis will be reduced, and the pink foamy sputum will also be reduced.