Apparently there is a connection between caffeine and headaches. Specifically, the lack of caffeine causes headaches.
Gee, that's nothing new, you say. We all knew that. And I'm sure you're right.
We've all heard of the headaches caused when trying to quit drinking coffee, or taking in any form of caffeine. Apparently caffeine has the effect of opening the blood vessels so that more blood can get to the various parts of the body. More blood = more oxygen. That's why we get the feeling of clarity when taking in caffeine, and the feeling of light-headedness when we take in too much. Trouble is, when you quit, your blood vessels are used to getting a certain amount of stimulation to open them up, and they get used to certain times of the day that the extra stimulation will be coming.
So here's the problem. When no caffeine comes, the blood vessels still expect to expand, and prompt themselves for it. No caffeine comes, and the result is an inflammation of the blood vessels and surrounding area. Inflammation = pain, and hence the headaches.
Now, having been a heavy user of caffeine products, I just recently experienced first hand all the symptoms of major withdrawal. On Sunday I began my ordeal, and found the base of my skull pounding by Sunday evening. I was in bed by 8pm, and didn't arise until 7am the next morning. The following day, Monday, my headache set in at 8am, and, at 1pm I was struggling with hot-flashes, cold-sweats, sluggishness, fog-headedness, and a pounding headache in the base of my skull. By 5pm I was vomiting, with the shakes. Mysteriously, by 730pm the headache had all but lifted. Tuesday, the headache set in at 10am, pounded the base of my skull for several hours in a thick fog, then lifted again around 6pm. Today, Wednesday, the headache only managed to set in around 2pm, and will most likely lift by the end of the evening.
Why the time frame? I can only imagine that it is because of my use of coffee during the normal business hours. I normally have my first cup of coffee at 8am, a second one at 10am, another at noon, and then a few more as the day goes by. Never later than 5pm. So that would explain my body getting used to caffeine at certain hours, and the headaches lifting at the later part of the day.
As an aside, one of the pages I consulted before beginning this ordeal suggested that the majority of headaches in the U.S. are caused by caffeine withdrawals, rather than other symptoms. The argument seems valid enough, since part of my caffeine cleansing requires that I drink no more Cola, eat no more chocolate (big caffeine culprit), and stay away from various random pre-packaged foods, more than one of which contains a random sampling of caffeine. Apparently there is more than one reason than great taste that we return to the same prepackaged foods...