What Causes Intermittent Headache?

Help me knowing the problem from a sudden headache My wife has facing the sudden headache problem once in a week now. The headache goes for 8 to 10 hours, in which 4 hours are quite unbearable for her. She just doesn’t listen anything and want to lie down on bed, even that doesn’t lessen her pain. And after few hours she woke up and behaves like hangover person for an hour or two and then everything gets normal. She takes some painkillers medicines that lessen the pain, though but remain on bed like a dead body crying in between the hours. She has this problem before she gave birth to my lovely son but that used to come once in year. From last 2 years she is having this sudden occurrence quite rapidly. A friend of mine who is Dentist suggested me to visit ENT (ear, nose, throat doctor) and told me that it is not a case of Neurologist. I am living in very small city of India so willing not to avoid this problem, so want to go to big city here for specialist. Please help me knowing what exactly is this case? Why she has having such a bitter pain and which doctor I should visit, ENT or Neurologist? Thanks for reading this. Manish Mishra