A related discussion,
head pain was started.
I have the same problem, It started like a month ago, Did you find out what causes it?
I just started experiencing the same thing. Did you ever find out what it was?
Consider calling your local ER and speaking with the triage nurse and especially if you have neck stiffness, vomiting or nausea or a dilated pupil in one eye. It could be anything... I know there is a condition that is called temporal arteritis that can cause headaches as you describe.
Good luck !