Illustrations of Unexpected Infant Sleep Deaths

States of arousal describe an infant’s physiological and behavioral condition during sleep, wakefulness, and activity. These states are regulated by the circadian rhythm, an internal biological clock that organizes daily patterns of rest and alertness. During infancy, arousal is commonly classified into five states: regular sleep, irregular sleep, drowsiness, alert inactivity, and waking activity.Regular and Irregular SleepDuring regular sleep, an infant’s eyes remain closed, breathing is slow...

Crying is an important form of communication during infancy, and different crying patterns can signal different needs or states. Infants can produce different cries associated with hunger, anger, and pain. These patterns vary in rhythm, intensity, and onset, helping caregivers recognize what an infant may be expressing.Types of Infant CriesThe basic cry is often associated with hunger. It typically follows a rhythmic sequence of crying, a brief pause, and an inward breath. This inhalation may...