Thanks so much for all the input but actually they've run me through all the stress tests, etc. to make sure it's nothing serious. I'm healthy as can be - resting pulse around 68 and bp last week of 118 over 70. I hadn't thought about caffeine. I do have a cup or two of coffee in the mornings and the headaches are worse in the mornings than in the afternoon. They seem worse in the heat too. Of course, I rode 15 miles this morning before work and right after my coffee with no headache. Go figure! All I know is that when one hits me its sudden, severe and pounding and will dull after exertion and last for 2-3 days.