When Is One Prone To Syncope?

hai sir. my son aged 13 years studing 8th standard,very active and good behaviour,last year suffered with syncope symptom like fainting only.2 times with a gap of 4 months, eeg and ecg every thing normal,doctor advised us regarding syncope and say don t wprry about that.after one year we joined him a residential school which he is not interested.and also pressure on studies,at that school the same repeated two times with a gap oa 10 days.now I changed him to his old school but here at the time of examnation heconfused with the question paper and fainted few seconds.to wakeup from fainting he need some water to wash his face .after that he was very normal. so kindly give us advice sir.