Hi, thanks for the query; what is his age & since how many months or years he is having these troublesome symptoms? We have to rule out 2 possibilities here; whether this is migraine/cluster headache which can be precipitated by stress, usually is confined to half side of head with associated giddiness, nausea, vomiting, blurring of vision etc. or if this is underlying depressive illness with predominant anxiety symptoms which are exacerbated by stressful situations. How is your friends overall mood, work efficiency? is he into use of alcohol, tobacco products, whether he is frequently irritable, complains of tiredness, aches & pains? Consult your GP/Psychiatrist for a detailed evaluation or get back to me for further assistance. Hope this helps; good luck