Sleep talking, formally known as somniloquy, occurs when a person is fully asleep and completely unaware that they’re speaking. The speech can be anything from full monologues to short sentences, demands, confessions or just plain gibberish.
Thankfully, most things said during a spell of sleep talking are random and irrelevant — so if your friends or partner were to overhear you talking in your sleep, there’s a good chance there wouldn’t be any negative repercussions (except maybe a bad night’s sleep).
For some people, alcohol, drugs, and stress may be to blame for sleep chatter — so if you’ve been told you talk in your sleep, it may be worth cutting down on those things for a while, to see if doing so helps.
Incidentally, many people are unaware that they talk in their sleep until told by others — so if you normally sleep by yourself, you may be talking in your sleep without knowing it.