Poisoned, Again?

I wonder what actually causes headaches, anyway. I'll have to Google that one of these days. Because sometimes it feels like your brain has swelled so much that it's going to burst through your skull, and there's nothing else that could possibly cause that much pain.

That's what happened to me at 4 a.m. this morning. I woke up with an absolutely mind-numbing, brain-splitting headache. I only get migraines once a year or so, but this was a do-sie. I have no idea where it came from, but it woke me out of a deep, dreamless sleep. I rushed to the bathroom and popped three ibuprofen, expecting to fall asleep again twenty minutes later. But it never kicked in!!

Three hours later the sun had started to come up, and I had to transfer my tossing and turning to the bathroom floor (the only totally dark place in our condo) because the sunlight was making the whole thing twice as intense. I felt like I had been whacked in the back of a head with a two by four. My eyes felt like they were going to pop out of my head. The throbbing was indescribable. I wanted to cry, but I knew that would just make everything worse. And on top of everything I felt ready to hurl at any moment.

Finally, around 8:15 a.m., the pain had ebbed enough that I was able to drag myself into the shower to get ready for work. I arrived very late and still with a persistent (but, by then, manageable) headache. What could have caused such a thing!?

I did go to happy hour the night before... But I had one sangria and shared an appetizer, and was home by 8 p.m. Nothing out of the ordinary. However, my boss has since informed me that she definitely thinks it was that sangria that did me in. Apparently, this particular drink can be mixed with all different kinds of wine and booze, and maybe the combination just added up to bad news for little ole me. I guess I'll never know for sure, but I'm still wondering...

What exactly does cause a headache?