A one-and-a-half-year-old baby with bronchitis and coughing symptoms should first be treated with anti-inflammatory therapy, choosing the appropriate anti-infective drugs according to the type of pathogen. If it is a bacterial infection, you can take anti-inflammatory drugs of the cephalosporin or penicillin type orally; for viral infection, you can choose antiviral drugs such as Qing Kai Ling, Bai Rui Granules, and Pediatric Shuang Jin Qing Fever Oral Liquid; for mycoplasma infection, you can choose azithromycin or erythromycin treatment. If coughing and phlegm are present, you can give phlegm-relieving herbal medicines, such as expectorant spirit oral liquid and pediatric phlegm-relieving cough granules. If the child has especially high phlegm, you can also choose western medicine, such as oral solution of Ambroxol hydrochloride and acetylcysteine granules. You can also give your child nebulizer treatment. The medications to reduce phlegm are acetylcysteine for inhalation and the medications to calm asthma are budesonide and terbutaline. The child should also drink plenty of water and drain the back regularly to help dilute the sputum and make it easier to expel. You should also keep the air in the room and give your child a light diet. If the above treatment does not work well, you need to bring your child to the hospital to be listened to by a doctor to see if there are any problems with the lungs or to take a chest X-ray to further clarify whether there is pneumonia.