A "sigh" is a natural, often involuntary, exhalation of breath that can express a range of emotions, such as relief, sadness, or frustration. It typically involves a longer and deeper breath out than usual, sometimes accompanied by a slight sound. Sighing can serve as a way for the body to release tension or communicate feelings to others. In psychology, sighing is sometimes linked to emotional states and can indicate stress or fatigue. It may also occur during moments of contemplation or when someone is processing their thoughts. Overall, sighing is a common human behavior that reflects our emotional and physical states.