People talk in their sleep, a phenomenon known as somniloquy or sleep talking, because parts of the brain remain active and not fully transitioned to sleep mode. This can lead to vocalizations occurring during various sleep stages, including both REM (rapid eye movement) and non-REM sleep. Sleep talking may be linked to genetics, stress, anxiety, sleep disorders, or mental health conditions, though the exact cause is still not fully understood. It often happens during partial awakenings or disruptions in sleep cycles, and can sometimes coincide with dreaming or other parasomnias like sleepwalking or night terrors. Most people are unaware they talk in their sleep unless told by someone else, and while it usually isn’t harmful, it can be a sign of underlying conditions in some cases. This behavior happens because the brain is in a mixed state where some parts are asleep while others remain partially awake or "awake-like," leading to speech production without conscious awareness. Sleep talking is more common in children and tends to decrease with age. Stress, lack of sleep, mental health issues, and certain medications may increase its occurrence. Furthermore, a disorder like REM behavior disorder can cause more vivid and active sleep talking along with physical movements during dreams.
