Frequent Headaches. To know the reason.

Hi, I am having frequent headaches for a couple of years now. Earlier it used to be less frequent like once a month and i used to take pain killers. But the frequency has increased now. I almost gets headache once a week. I did the blood check, eye check and other basic checks with my family doctor a year back, but could not diagnose the issue. The headache is normally starts at one side and in an hour it pounds on entire head, sometime feels like its hot inside there, but i dont get fever or cough. Sometimes I got boils around my head and body too. But those are not painful, comes and goes. I am out of options than to take pain killers. Can someone suggest whom should I consult or what test i should take to know the reason.