What causes a persistent headache?

Persistant Headache: I would like to know where your headache is and how severe it is, how long ago it started, and what makes it better or worse. Have you suffered an injury? Are you on any medications? Have you changed your diet or what you drink recently? Have you stopped coffee or stopped Ibuprofen or tylenol (acetaminophen) after regular use? Could you be low in magnesium? Are you dehydrated? Keep a headache diary.

Many possibilities: It depends on how long have you had it, constant or not, location on head, precipitating events, any associated neurologic symptoms, worse in AM or PM. Causes range from needing glasses (very common at your age- do your parents wear glasses?) to neck muscle stress, to sinusitis, to medication side effects, to serious intracranial disease- you should see your primary care physician for help