The cough is strong at night. 1. firstly, most of it is due to the fact that after lying down, it is easier for the organism to discharge phlegm. This is because in a horizontal state, the phlegm in the stomach is more easily discharged from the body through the airway, and when the phlegm is discharged, it will stimulate the nerves in the airway or pharynx, leading to coughing. 2. Secondly, it is allergic to the dust mites on the bed quilt, mattress or pillow at night, which often cause coughing and require mite removal treatment. 3. The best way to humidify the room is to use steam, which is water vapor, and steam will appear when boiling water for 2-3 minutes, and then the room will have a lot of steam, so that the room is not too dry at night. Because the general winter room is airtight, but in the summer, the natural humidity will be enough, there will be no such condition.