Well, thyroid problems are pretty common with lithium, usually after being on it for some time (years). But thyroid is easily treated, albeit with another pill. Or you can stop it to see if the thyroid improves but I think most people just take the thyroid med. It's a no-side effect, easy pill.

The hair thing usually happens gradually and can be helped as I noted above. For me it got really bad because I had toxicity for a prolonged period. That was because I didn't get my labs done when they were due and then it took a while to figure out what was going on. If I'd had that level done and the toxicity caught sooner I'd have been in better shape. (The hair thing is sometimes related to thyroid and was for me.) I also was on another med that can affect hair growth.

Getting your labs done on time, every time they are due, is really important with the lithium. And calling and asking for labs if something doesn't feel right is important too.

Sorry to scare you.