Pink foamy sputum is one of the most common manifestations of pulmonary edema, and the cause of pulmonary edema is mainly heart failure caused by various diseases, such as having severe hypertension, or acute heart failure caused by coronary heart disease, and acute pulmonary edema occurs in patients with acute heart failure, which causes pulmonary stasis, and the aggravation of pulmonary stasis can lead to plasma exudation from the capillaries in the alveoli, and plasma infiltrates into the alveoli to mix the gas, thus pink foamy sputum is formed. Therefore, the appearance of pink foamy sputum requires prompt identification of the specific cause of pulmonary edema, as well as treatment to reduce cardiac load, such as the use of diuretics and vasodilators.