Is headaches in a 10 year old normal. i have taken him to a gp and he advised that it could be growing pains or a pain due to post nasal drip?

Maybe. Maybe not.: Most people (including kids) get a headache at some time, such as from colds, infections, lack of sleep, too much driving, long hours on the computer, stress at work, etc... Over-the-counter options include Tylenol (acetaminophen), Motrin or Advil (ibuprofen), and their generic brands. A bad or increasing headache, recurrent headache, weird headache, or with other worrisome symptoms need an exam.

Kids usually: complain of a "headache" when something else is "wrong" (eg: fever, sore throat, school problems...yup school problems) I would suggest that if its a single episode do a mommy(daddy)"examination....twice..a visit to the Pediatrician is strongly advised! Hope this is helpful Dr Z