A three-and-a-half year old child with a bad cough at night may have allergies, pneumonia or bronchitis, which can be treated with oral or nebulized inhalation medication in conjunction with the cause of the cough. 1. If the cough is caused by allergies to cold air, pollen or dust mites, first of all, avoid the child’s contact with allergic substances to avoid aggravation of the symptoms, and under the guidance of the doctor, oral cetirizine or loratadine and other drugs treatment. If necessary, you can also take a small dose of oral prednisone to improve the symptoms. 2. If the symptoms are caused by pneumonia or bronchitis, you can apply phlegm-reducing drugs, such as Ambroxol Hydrochloride Oral Liquid. 3. If the indoor temperature is low and the baby is cold at night, you need to keep the baby warm. 4. If cold symptoms occur, you also need to use pediatric cold granules to relieve. Children coughing at night may also have other reasons, it is recommended to go to the hospital in a timely manner, to clarify the cause of the disease after targeted treatment.