Possible causes of face swelling after lung surgery include: pulmonary heart disease cardiac insufficiency, renal impairment, drug allergy and so on. 1. Pulmonary heart disease: when the disease progresses to the late stage and is more serious, it will cause pulmonary edema and left heart failure, at this time, facial swelling can occur. 2. Kidney function damage: when suffering from kidney disease, swelling may appear due to kidney function damage. 3. Drug allergy: after lung surgery, you may need to cooperate with certain drug treatment, and when drug allergy occurs, facial swelling may occur. When face swelling occurs after lung surgery and continues to be unrelieved or aggravated, it should be reflected to the doctor in time, and the appropriate treatment should be chosen under the doctor’s guidance.