Sleep takes up most of the time in the life of infants and toddlers. Therefore, parents are very concerned about their babies’ sleep. Adequate sleep is very important for both physical and intellectual development of infants and toddlers. Because, sufficient sleep can promote the development and development of brain function, which is conducive to brain energy storage, memory consolidation and physical recovery. Lack of sleep, on the other hand, can affect the development of the child’s cognitive functions, damaging the frontal cortical functions of the brain, leading to changes in emotion and attention, and triggering deficits in language and abstract thinking functions. How long should my baby sleep in a day? In terms of total sleep time, the younger your baby is, the more sleep he or she will get. Babies from newborn to 2 months sleep 14-18 hours a day, babies from 2-4 months sleep an average of 14-15 hours a day, and babies from 4-6 months sleep an average of 13-14 hours a day. However, there are individual differences in sleep duration and not every baby is the same. Some babies sleep less but are in good spirits when awake and their diet is not affected, so there is nothing to worry about. How long does it take to wake up after sleeping? Newborns do not have a circadian sleep pattern, often reversing day and night, but as their nervous system matures, they will slowly develop a relatively stable circadian pattern of sleeping and waking. Also, as they get older, their daytime sleep time shortens and their waking time lengthens. Newborns wake up for 1-2 hours every 3-4 hours, and at 4 months, they can wake up for 3-4 hours. 3 months later, the daytime sleep time slowly decreases, with a fixed nap time and a long sleep at night. There are also about 44% of babies who start sleeping long at night at 2 months. 6 months old babies have a maximum sleep period of 6 hours at night, and the average sleep time at night from 6 months to 5 years old is about 11 hours. Will my baby be hungry when he or she goes to bed at night? Some parents worry that their babies will be hungry if they don’t eat at night, but in fact there is absolutely nothing to worry about. According to research, a 4-month-old healthy full-term baby can sleep for 6 hours without eating, 5 months can sleep for 9 hours without eating, 6 months can sleep for 12 hours without eating. And if the baby does not eat at night, he or she will eat more during the day, so parents do not have to worry about the baby’s nutritional deficiencies. But don’t let your newborn’s nighttime sleep last more than 4 hours, and your newborn should wake him up to feed him even if he sleeps for more than 3 hours during the day. Deep sleep and light sleep alternate. Sleep is divided into light sleep (oculomotor sleep), and deep sleep (non-ocular sleep). In infancy, during light sleep, the baby may show various strange movements, sometimes sucking, sometimes smiling, sometimes looking like making a face, sometimes pouting, sometimes there are big dance-like body movements, the body looks like stretching, sometimes there is a sudden tremor, and occasionally there are vocalizations, irregular whistling, and the eyes move under closed or semi-closed eyelids. Light sleep accounts for most of the infant’s sleep time in the first 2 years of life. Light sleep plays an important physiological and psychological role in infant and child development. Some studies have shown that light sleep increases the synthesis and metabolism of proteins in the body during light sleep, allowing for the retention of new knowledge learned. Therefore, parents should never worry because their babies make some strange movements during light sleep, nor should they interrupt their babies’ light sleep by waking them up or picking them up. In the neonatal period, sleep starts with light sleep, goes into deep sleep after about 15 minutes, then goes back into light sleep, and finally wakes up. Each sleep cycle is equally divided between deep and light sleep. Sleep behavior and physiological functions mature during the first 2-3 months of life. The pattern of sleep gradually changes over the 3 months to start with deep sleep (adult-type sleep starts with deep sleep), and the duration of deep sleep is prolonged, with deep sleep being twice as long as light sleep. By 6 months of age, 82% of babies’ sleep begins with deep sleep. 2-5 years of age, light sleep gradually decreases from 30% to 20%-25% (equivalent to adult levels). Also there is less physical activity during light sleep, and light sleep is more pronounced in the second half of the night, moving towards the adult type. Sleep cycles also lengthen with age, averaging 45 minutes per sleep cycle for newborns and 60 minutes per sleep cycle at 2-3 years of age. The development of sleep habits begins at 4-6 months of age. Babies from newborn to 2 months of age rarely last more than 4 hours per sleep. This is because the baby’s nerves are not yet mature enough to enable him to relax into sleep on his own. Parents can help their baby fall asleep by wrapping, gently rocking, feeding, and using a comforting pacifier without worrying about spoiling the baby or developing permanent bad habits, because babies up to 3 months old do not yet remember their surroundings. But from the age of 4-6 months, we should cultivate good sleep habits in babies. How to develop baby’s sleep habits? In order to cultivate good sleep habits, parents need to create a quiet, darker sleep environment with appropriate temperature and humidity, set a reasonable wake up and sleep time and strictly enforce it. It is recommended to go to bed early and get up late, and it is usually better to go to sleep at 8:00 pm. If your baby sleeps late, you can wake him/her up a little earlier in the morning to gradually advance the bedtime. Appropriate naps during the day, too much sleep during the day or too tired during the day, or the daytime sleep is too close to the night sleep, sleep at night is not good. Do not play too excitedly 1-2 hours before bedtime, you can do some quiet activities, such as reading a book, telling stories, etc. Take a warm bath before bedtime and do baby touch, which is also good for your baby to fall asleep. Don’t eat too much before bedtime, and don’t be hungry. Do not let your baby fall asleep with a pacifier or soother, and avoid the bad habit of hugging, patting and shaking before bedtime, because if you use the above methods when you fall asleep, your baby will still need to use the above-mentioned accompanying sleep behaviors to fall asleep when he or she wakes up in the middle of the night. The specific ways to develop good sleep habits may not be exactly the same for each baby, but the basic principle is to give as little comfort as possible and spend more time letting your baby learn to fall asleep. What’s wrong with my baby crying in bed at night? It is very common for babies to cry at night. Some are due to bad sleep habits, such as babies who depend on sleeping with their partner, in which case parents should try to gradually reduce sleeping with their partner and develop good sleep habits. There is a basic fixed time every night, the occurrence of unexplained crying, and can not be comforted, but after a period of crying baby back to normal, and does not affect the baby’s spirit, food, parents do not need to worry too much about this situation. However, for babies born prematurely or suffocated, if they cry at night and are not comforted by any method, it often indicates brain damage. There are also babies who usually sleep well and suddenly cry at night and are not well comforted, possibly because they are sick. There is also a phenomenon of alternating violent crying and quietness, accompanied by abdominal distension and vomiting, which may be intussusception, an acute abdominal disease in infants, and should be seen by a pediatric surgeon immediately. In addition, infants who sleep excessively or even do not know they are hungry and act excessively “honest” should be aware of the presence of congenital hypothyroidism.