We all know that in childhood there is “ADHD” this disease, but if we look more carefully, we will find that most of the diagnostic criteria for ADHD only applies to school-age children, that is to say, refers to the age of 6 years old and above school-age children can be diagnosed as “ADHD”. But we often see a lot of children under the age of 6, and even infants and young children will be “moving” all day long, attention is obviously not focused, is it that infants and young children do not have “ADHD”? Indeed, according to the current diagnostic criteria, it is difficult to make a diagnosis of “infantile hyperactivity disorder”, and in our usual outpatient clinics will rarely diagnose an infant or young child with “hyperactivity disorder”. In fact, ADHD exists not only in school-age children, but also in infants and toddlers. The etiology and pathogenesis of ADHD are not yet fully understood, but it is generally believed that ADHD is caused by a combination of genetic, biological, environmental and psychosocial factors, rather than a single acquired factor, and the “innate” factor is also very important, which determines that ADHD can be seen at any age, including infants and toddlers. This means that ADHD can be seen in children of any age, including infants and toddlers. Many children with ADHD are hyperactive from an early age, and some mothers even recall feeling that their fetus moved a lot during pregnancy, and that the “movement” became more pronounced after birth. In the neonatal period, the child appears to be particularly active, hands and feet moving about, even to eat the milk is not quiet, sleep less, immediately after waking up will cry, want to be carried by adults. Infancy is mainly manifested in poor regularity of life, hyperactivity, restlessness, irregular behavioral changes, excessive crying, easily provoked, mother-child relationship is not coordinated, mothers often resent their children than other children difficult to raise. To early childhood parents will find their children are different from other children, too much activity, disobedience, difficult to discipline; some of the performance of sleep disturbance, feeding difficulties, chasing; some throw toys, play for a while on the boredom, personality quirks, easy to be hurt, and often have urination and other manifestations. Active is the nature of the child, the younger the age, “move” the more obvious the possibility of hyperactivity in infants and young children is also easy to be accepted by the people, and infantile hyperactivity on the child’s life and learning impact is relatively small, and therefore the degree of concern is not as high as for school-age children, parents bring their children to hospitals to see a small percentage. In addition, if a child is given the label of “ADHD” from an early age, it will cause a lot of psychological pressure on both the child and the parents, and will also have a negative impact on the child’s future mental and behavioral development. Therefore, there is generally no need to diagnose “infantile ADHD”. However, if parents and teachers find that the child has particularly obvious hyperactivity and inattention in infancy, early diagnosis and behavioral intervention should be carried out to prevent further aggravation of the condition and to facilitate the healthy development of the child’s mental and behavioral health.