Since how many days have you been suffering from headache? Where exactly is the headache (frontal, at the back of the head, on the sides, on one side of the head etc.) Type of headache? (throbbing, dull etc.) Relief with medication? Aggravating factors? Associated visual disturbances? watering of eyes? nasal obstuction? These are just some of many questions that need to be answered to be answered to diagnose the cause of your headache and plan further management.