About two months ago I stopped drinking coffee (more or less--I was drinking around half a pot a day and now I might have a cup in the morning, about a third of the time), and started drinking tea. Right now I'm drinking ~5 cups a day of tea or so. At night I have earl grey, and the rest of the time it is plain black tea. I don't add milk or sugar, and tend to brew it strong.
I thought it was healthy (or at least relatively harmless), but I read that too much tea causes excess fluoride to build up in the thyroid gland. Am I drinking too much? I know of the danger of dehydration with caffeine, but I make sure that I am properly hydrated so that isn't a problem.