The main causes of attention deficit hyperactivity disorder, also known as ADHD, are genetic factors, neurological factors, pregnancy and childbirth factors, as well as dietary and nutritional deficiencies, and possibly family and psychological factors, as follows: a. Genetic factors refer to the possibility that ADHD is a polygenic genetic disorder, especially when there are relatives with ADHD, schizophrenia, depression and other psychiatric disorders within three generations in the family line, when the child The probability of developing ADHD is very high. Neurological factors, such as imbalance of neurotransmitters in the brain may be related to ADHD, or it may be that the neuromyelin sheath is not particularly mature, so the child is particularly prone to brain hyperexcitability, which is why the problem of attention deficit occurs. Third, pregnancy and childbirth factors, such as the mother during pregnancy or childbirth problems, especially during pregnancy, pregnant women smoking, drinking, drug use, etc., when the delivery of premature birth, birth canal injury, etc. may occur children hyperactivity. Fourth, diet and malnutrition factors, mainly is the child may be taking drugs, poor diet or malnutrition resulting in iron deficiency, elevated blood lead, low blood zinc levels, etc., may appear ADHD. Fifth, family and psychological factors, there may be intergenerational parenting problems, the family does not give enough education and support, encouragement, the child may have character defects, these aspects may lead to ADHD. To sum up all the above reasons, ADHD is very much a combination of factors that occur.