Pulmonary edema is diagnosed on the basis of patient’s symptoms, physical examination and lung ultrasound. 1. Symptoms: Coughing, coughing up sputum, wheezing, dyspnea are the most common symptoms of pulmonary edema, often with telangiectasia, and the patient may also have irritability, asphyxia and cyanosis, and in severe cases, even coma. 2. Physical examination: In most patients with pulmonary edema, abnormalities can be detected on lung auscultation, and wet rales can be detected. In the early stage of cardiogenic pulmonary edema, the wet rales are at the base of the lungs, and as the pulmonary edema progresses, the range of wet rales will expand. 3. Ultrasound of the lungs: Ultrasound of the lungs can be a useful diagnostic tool in the diagnosis of pulmonary edema. Ultrasound findings of bilateral, diffuse, respiratory-synchronized, and comet-caudal lines emanating from the pleura are highly suggestive of cardiogenic pulmonary edema. Pulmonary edema is a pathological condition in which abnormal infiltration of fluid from the pulmonary capillaries into the interstitium and alveoli exceeds the compensatory capacity of lymphatic return, resulting in an abnormal accumulation of extravascular fluid in the lungs. It is recommended that if patients have symptoms such as dyspnea, they should go to the hospital in time for consultation and do physical and ultrasound examinations to clarify the cause of the disease.