A second grade elementary school student came to the clinic with naughty and hyperactive behavior, inattentiveness in class, and decreased academic performance. He was diagnosed with ADHD after examination by the doctor, and his symptoms improved significantly after treatment. However, children who are naughty and hyperactive may not always have ADHD, because there are many reasons why they are naughty and hyperactive. Some of the children who visit the clinic for naughty and hyperactive are normal children, some have ADHD, some have mental retardation, some have tics, some have adjustment disorders, some have learning difficulties, some have certain nutrient deficiencies, and some have conduct disorders or other problems. Therefore, although the prevalence of ADHD in school-age children is as high as 5%, it should not be assumed that all children with ADHD are naughty and hyperactive. On the other hand, some children with ADHD may not necessarily be mischievous and hyperactive. ADHD, also known as attention deficit hyperactivity disorder, is a behavioral disorder characterized by inattention, hyperactivity and impulsivity, and may be accompanied by learning difficulties. It is clinically divided into three types: attention deficit hyperactivity mixed type, attention deficit dominant type, and hyperactive-impulsive type. The attention-deficit-oriented hyperactivity type is not obvious, but it shows inattentiveness, distractibility, slow homework and poor academic performance. As a parent, when you find that your child is naughty and hyperactive compared to children of the same age and gender, on the one hand, do not subjectively believe that your child is deliberately working against parents and teachers, thus criticizing and scolding, or even physically punishing; on the other hand, it is best to visit a specialist clinic to clarify the specific causes and take targeted treatment, so as not to affect the healthy growth of your child.