Welcome to HealingWell and the Bipolar forum, I am glad that you found us.
I was on Lithium for about
3 years in the past, and it was a great med for my moods; but it can have a lot of side effects. One major thing I can tell you is that it is important to drink plenty of water. I would suggest no less than 6-8cups a day, but remember not to over do it. This is especially important in warmer weather.
Other than that, meds react differently from person to person so you may not get the same side effect as the next person who takes it. All I can tell you is that the higher the dose the greater risk of side effects, but you should bring all your concerns up with your pdoc when you see them next. I didn't really have severe side effects that I know of, just minor ones that were really bothersome.
Please don't hesitate to ask any questions.