Coughing is normal; night coughing can be because of an airway infection viral or bacterial. It can also occur because of an allergy. Even sleep apnea can cause coughing at night. You can try dusting your room and home often. Keep your bed clean and dust-free. Use a humidifier if needed. You need to take care of triggers that may cause allergy, which is leading to coughing. If the cough becomes severe, consult your health professional.
Cough gets worse at night & sometimes it happens with me. The whole day I am okay & before going to bed I start coughing. Try gargling with warm salt water before going to bed.
This is not uncommon. Coughs get worse at night. Do you think this is due to a cold/flu type of situation or something like GERD which can have a night time cough. Gerd is acid reflux. If you think it is post nasal drip from his cold, a very common reason to cough more at night, propping his head up a bit more when sleeping can help. Adding pillows, towels under his pillow, etc. Does he use a humidifier? He could try some tea with honey. There is always cough medicine. But I am not a huge fan of cough medicine because coughs are supposed to move gunk through our lungs. If we don't cough, it sits. Festers. Possibly goes from being a cold to something like bronchitis which is bacterial. No shortness of breath, right? https://www.medicalnewstoday.com/articles/319498#home-remedies