Has he been tested for mononucleosis? Has he had his heart and blood pressure checked recently? Symptom checker on this site says headache, tiredness and cough can be symptoms of mono. It also says that tiredness, cough, and dizziness can be signs of a heart attack & if the pain is in his left shoulder, I know that can be another sign of a heart attack in males. It also says
are alls symptoms of flu and the common cold. But if he has not been stressed out lately, those last two probably wouldn't drag on that long & with his history of stroke, he really should go in to get evaluated!