More than two-thirds of people have talked in their sleep at some point, according to a recent report. This phenomenon, known as sleeptalking, falls under the category of parasomnias—unusual behaviors or experiences that occur during sleep. While it is common in both children and adults, it is more frequently observed in children. Generally, sleeptalking is harmless unless it happens often or causes disturbances, such as waking up others or being disruptive. Sleeptalking can occur in any stage of sleep, including REM sleep, the phase associated with vivid dreaming. During REM sleep, the brain is highly active, and the body usually experiences a temporary paralysis to stop people from acting out their dreams. However, during sleeptalking, the brain regions responsible for speech may become active, while the parts that normally suppress speech are inactive. This can lead to a range of vocalizations, from mumbles and whispers to full sentences, often without the person being aware they are speaking. Research suggests that what people say while sleeptalking often relates to their dreams. In about 80% of cases during REM sleep, the words spoken align with the content of the dream. However, these utterances are usually incoherent or fragmented, and may sound like the person is having a conversation or experiencing a conflict, even when no one else is present. This lack of coherence is a key reason why sleeptalking is often difficult to understand when heard by others. Sleeptalking is more common in children, possibly due to the higher proportion of slow-wave non-REM sleep they experience. As people age, slow-wave sleep decreases, which may explain why sleeptalking becomes less frequent in adults. While it is typically not a cause for concern, frequent sleeptalking could be a sign of being overtired. If someone experiences regular sleeptalking along with other parasomnias like sleepwalking or night terrors, it may be wise to consult a sleep specialist for further evaluation.