Crying in infancy is described as a loud, high-pitched sound made by infants in response to certain situations.
Infants have a cry reflex that is a normal response to some stimuli, such as pain or hunger. Older children and adults cry for emotional reasons such as pain, fear, sadness, or frustration. Premature infants may not have a cry reflex, so they must be monitored closely for signs of hunger and pain.
See also: Crying in childhood