Baby always cough in the middle of the night what reason

The baby always coughs in the middle of the night. First of all, it is considered that the baby has variant asthma, which is caused by nocturnal asthma attack; secondly, it may be that the baby has symptoms of cold caused by nocturnal cough. In addition, it is not excluded that the baby eats too much before going to bed and coughs caused by food reflux at night.