Coughing with a lot of white phlegm when lying down may be bronchitis, cardiac insufficiency and so on. Bronchitis is recommended to take cough and phlegm medication. Cardiac insufficiency is treated with diuretics (furosemide), cardiac glycosides (digoxin), vasodilators (sodium nitroprusside) and other drugs. Once lying down, coughing with a lot of white sputum, bronchial infection is more likely. Generally need to take cough and phlegm medication, commonly used drugs are dextromethorphan, aminoglutethimide and so on. It is recommended to check the blood routine, if there is a bacterial infection, you also need to take amoxicillin, cefaclor and so on. Patients with cardiac insufficiency, there may be pulmonary circulation stasis, pulmonary edema, when lying down, the return blood flow increases, usually aggravate the symptoms, need to use furosemide, digoxin, sodium nitroprusside and other drugs to treat. It is recommended that patients take medication under medical supervision to avoid aggravation of the condition.