Signs in dream??

Do you believe your dreams give you signs? Such as, losing teeth in a dream meaning something bad is going to happen or a loved one is going to pass away? I don't really believe it but my bf randomly woke up from a nightmare he had, breathing hard & it scared me. I asked what happened & he just told me to find him a dentist. He said he had a dream 2 of his teeth fell out & now he's worried that it's him that something will happen to. He's taking it very very serious & gets offended when I say "If you believe in that stuff then yeah it'll probably happen" & etc. No matter what I say he's gonna get upset so I wasn't sure what to say. I think he left to work upset as well.