Hi Doctor, I am 27yrs Old. I usually get severe headache only on the left side once in every fortnight. It would be so severe that I feel like banging by head. I cant bare light and sound at that time. I get releaved when I take a pain killer. This has been happening since 2005 when I was a student. Please suggest me what could be the problem and whom to consult and what kind of scan that I should get it done.