Xiao Li is 11 years old, a 5th grade student, in the eyes of parents and teachers she is a quiet girl, very obedient, but since the first grade teachers often reflect that the child does not listen carefully in class, easily distracted, do not know where the teacher spoke of when asking questions, do not finish, homework procrastination, often careless mistakes, more and more parents can not stand is quite smart looking child’s grades continue to decline, and even The parents tried all sorts of ways to educate the child but did not achieve good results, so they had to take the child to the hospital to consult where the problem lies, after the doctor examined the child was diagnosed with ADHD, but the parents are confused, the child is very honest, not at all naughty, how can it be ADHD? In fact, there are three types of ADHD, namely attention deficit-oriented, hyperactive-impulsive-oriented, and mixed type. The attention deficit-oriented type is mainly characterized by easy distraction, laziness, sleepiness, lack of motivation, often accompanied by anxiety, depression, and more learning problems, but less character problems. The hyperactive-impulsive type is common in preschool and early elementary school children, with overactivity as the main manifestation, capricious impulsiveness, emotional instability; poor tolerance, impulsive and reckless; insubordination and self-control. In the early grades, they often do not have academic problems, but tend to combine serious rebellion, lying, discipline, truancy, troublemaking, and aggressive behavior, making them difficult to discipline. The mixed type, with both hyperactivity and inattention, represents the most common concept of ADHD and is often combined with oppositional defiant disorder, conduct disorder, and anxiety and depression disorder. Children with hyperactivity and mixed types of ADHD are easy to detect because of their outward signs of hyperactivity, but children with hyperactivity are not necessarily ADHD. The major difference between children with ADHD and children with mischievousness is that children with mischievousness often act with a purpose, plan and arrange their actions, differentiate between occasions, and adjust their behavior to match the occasion. Children with ADHD do not have this ability, and their “hyperactivity” is not selective in terms of the content of their activities or the occasions on which they engage in them, showing symptoms of hyperactivity and inattention regardless of the occasion. Children who are not hyperactive are not necessarily not ADHD. For example, attention deficit predominant type, which is common in girls, is characterized by inattention and hyperactivity, but often has more cognitive impairment, lower reading levels, lower co-occurrence of externalizing behavior problems (e.g., oppositional defiance, conduct disorder), and more impairment in social functioning, but responds better to medication than boys. Because hyperactivity and externalizing problems are less pronounced in girls than in boys, they are not easily detected by parents and teachers and should be a cause for concern.