Why do we talk in our sleep?

 My roommate told me the other night that I was talking in my sleep. I immediately panicked. Oh no, what did I say? I hope I didn't say anything too crazy? I hope she doesn't know about the weird dream I had last night. I barely understood it. She then told me she couldn't understand me. I breathed a sigh of relief. My dream secrets are still in my head. She was actually talking in her sleep the other night too. Lucky for her, I couldn't understand her either. But, why was I talking in my sleep? I don't even remember doing it.

Sleep talking, also known as somniloquy, normally occurs in children. Their young minds are still developing, so their sleep cycles are not quite complete yet. Five percent of adults - both men and women - talk in their sleep. Sleep talking can usually occur in families. This talking can range from small utterances to yelling and screaming.

Both my roommate and I only mumbled in our sleep so we didn't keep each other up with loud curses about our evil homework assignments. But why did it happen at all?

Some say that sleep talking occurs during the REM( Rapid Eye Movement) cycle of sleep. Others say it can happen in any cycle of sleep. This occurrence in most cases is harmless. But in some is the result of something more serious. Some people who sleep talk might have RBD (REM Sleep Behavior Disorder). This causes people to grunt, shout, yell and act out their dreams at most times violently. Night Terrors or Sleep Terrors can also result in sleep talking. People with this disorder usually have frightening screams and they trash and kick. They normally can't be woken up in this state. Children with it usually sleep talk and sleepwalk. NS-RED (Nocturnal Sleep-related Eating Disorder) can also cause sleep talking which induces eating while asleep.

Sleep talking can happen because of emotional stress, substance abuse, fever, certain medications, or a mental health disorder. Yet, lack of sleep, heavy meals, and stress could cause sleep talking. I guess my roommate and I need to skip the books at night and get some sleep.