Caffeine is such an ingrained part of most people’s daily life that we often don’t realize how much we’re getting. If you have fibromyalgia or chronic fatigue syndrome, it’s definitely something to think about.
We like caffeine because it gives us energy, and who needs energy more than we do? The problem with it, though, is that after the initial burst, it can make you feel worse. That’s true for everybody, but even more so for many of us — it artificially speeds up an energy-depleted body that may not be able to tolerate an increase in activity, and that can put you at risk for a symptom flare. It’s like an energy credit card with a really high interest rate.
http://chronicfatigue.about.com