Attention deficit hyperactivity disorder (ADHD), also known as attention deficit hyperactivity syndrome, is a common behavioral disorder in childhood. The obvious symptoms are inattention, lack of persistence, large activity and frequent changes in content, which may be accompanied by behavioral impulses and learning difficulties. Usually, the onset is before the age of 6, with more boys than girls, and the symptoms of school age are obvious, and some patients' symptoms can continue into adulthood.