If a child has drowsiness after a cold, it is mainly considered to be caused by the following serious conditions. First of all, it is caused by the symptoms of a cold in children due to a serious bacterial infection. If the child is suffering from a cold caused by a bacterial infection. In this case, the child’s mental state is often poor and the fever is recurrent. The effect of common cold medicine is not very good. In this case, the child should be given anti-bacterial infections, such as cephalosporin or amoxicillin, in a timely manner. When the bacterial infection of children’s colds is controlled, the mental state of children will improve. Secondly, it is caused by encephalitis in children who have a cold that is not well controlled and the pathogenic bacteria have invaded the child’s brain, which can cause encephalitis. In this case, children may also become drowsy. In this case, the child should be given timely anti-infection treatment, such as the application of third-generation cephalosporins, which can cross the blood-brain barrier.