Hi Strong Coughing (due to any cause including aspiration of food into the airtube either from stomach or while swallowing)increases pressure inside the skull(intracranial pressure) and can cause headache. There are certain rare causes for severe headache like bursting of weak and balloned out arteries supplying brain(berry aneurysms). More commonly coughing can be due to phlegm (due to infection of the sinuses licated in face and skull bones)dripping onto back of the throat causing cough.in this case the headache caused due to infection of the sinuses can be aggravated by cough. In any case if his headache is not severe /not associated with vomiting or blurry vision/inability to bend nech and touch his chin his chest)there is no emergency. Check whether he is abke to smile properly(without deviation of angle of mouth to one side),able to lift both his arms above shoulder level,and speak properly it is unlikely to be stroke. Hope this helps. Regards Dr.N.Ananth.