Lung cancer causing generalized edema may be caused by hypoalbuminemia, pericardial effusion, impaired kidney function, etc. It can be treated by supplementing albumin, using diuretics such as hydrochlorothiazide or pericardiocentesis. 1. Hypoalbuminemia: lung cancer is a kind of consumptive disease, which will lead to decreased appetite and food intake of patients, and in the long run, it will cause hypoalbuminemia, which will lead to generalized edema of patients. The patient can be helped to alleviate the symptoms of generalized edema by strengthening the patient’s nutrition and infusing albumin preparations. 2. Pericardial effusion: pericardial metastasis of lung cancer will limit the diastole of the heart, and the blood of the whole body can not return, resulting in generalized edema, which can be treated with diuretics such as hydrochlorothiazide and furosemide according to the doctor’s instruction, and pericardiocentesis is feasible for patients with serious symptoms. 3. Impaired kidney function: lung cancer patients may suffer from impaired kidney function during radiotherapy, which may reduce the filtration capacity of kidney and lead to generalized edema. Generally, diuretics such as hydrochlorothiazide can be used for diuretic treatment, and patients with ineffective drug treatment can undergo dialysis to discharge excess water and metabolic wastes from the body, so as to reduce the symptoms of generalized edema. Patients with generalized edema caused by lung cancer should go to the hospital in time, complete the examination, and give targeted treatment after clarifying the cause of the disease.