Regular caffeine consumption reduces sensitivity to caffeine. When caffeine intake is reduced, the body becomes oversensitive to adenosine. In response to this oversensitiveness, blood pressure drops dramatically, causing an excess of blood in the head (though not necessarily on the brain), leading to a headache.

This headache, well known among coffee drinkers, usually lasts from one to five days, and can be alleviated with analgesics such as aspirin. It is also alleviated with caffeine intake (in fact several analgesics contain caffeine dosages).

Often, people who are reducing caffeine intake report being irritable, unable to work, nervous, restless, and feeling sleepy, as well as having a headache. In extreme cases, nausea and vomiting has also been reported.

When I broke my extremely heavy caffeine addiction, I went haywire. For a few days I had the typical throbbing headache, then, the weirdness started. Firstly, I could not sleep, but I could never rest enough. My thinking is that my nervous system was hypersensitive to the newly absorbed levels of adenosine causing me to feel overly fatigued when I did not require rest. Then, the climax of my sickness came. I returned home from class and laid down for a nap around three in the afternoon. During my slumber I had the most vivid and amazing dreams I have ever experienced. Fifteen hours later, I woke up. Needless to say, that was an odd experience for me. Now, I am more or less as normal as I've ever been.

Log in or registerto write something here or to contact authors.