A 1.5 month old baby with cough and phlegm can be given cough syrup, heat-clearing and phlegm-eliminating granules, fresh bamboo lee or monkey jujube powder at home if the symptoms are not serious. To feed more water, gently pat the baby’s back, up and down, left and right. If you pat a part of the cough aggravated, it means that phlegm accumulates here, usually the scapula area, that is, the bottom of the lungs to collect phlegm, to focus on patting. You should also clean the phlegm from your baby’s mouth, keep the air fresh, circulating and moist, and don’t catch a cold. If the cough worsens, you need to go to the hospital for nebulization treatment. If the cough sounds deeper, has phlegm that is difficult to cough up, or is accompanied by more rapid wheezing and dryness around the mouth and lips, it means that a lower respiratory tract infection may have occurred. If a lower respiratory tract infection occurs, you need to go to the hospital to have your doctor auscultate your lungs and, if necessary, do X-rays of your lungs to find out if bronchitis has occurred. Once pneumonia or bronchitis has occurred, you need to be hospitalized immediately.