Syncope is the last noticeable symptom of asthma. The flow of blood stops being transmitted to the head. Thus, the human brain remains with this necessary liquid. Another cause of fainting is the heavy coughing; it is followed by the quick drop in blood pressure, which is not good for the nervous system. There is no need to provide the first aid. Move a person to the safe place is it happens somewhere in public. He or she will be awake in several minutes.