perhaps call NHS direct for advice if you are concerned, if you are in UK, haven't got the number to hand, but you can find it on web, they respond quite quickly. have you done any strenuous exercise lately, pulled a muscle in neck, stressed from work, allergies, sinus problems can also cause headaches, blocked nose, endless things, worrying abou it can make it worse. try NHS direct, sometimes its talking with someone that can alleviate the worry, or point you where to get help.