The causes of children’s drowsiness can be divided into physiological manifestations caused by sleep deprivation and overwork; and pathological factors such as the initial stage of infection, heart disease, electrolyte disorders, endocrine diseases and craniocerebral diseases. 1. Physiological manifestations: lack of sleep, overwork and other factors will cause the child to appear sleepy, poor mental performance. 2. Pathologic factors: (1) Early stage of infection: the child may show symptoms such as drowsiness, poor spirit, fever and rash. (2) heart disease: such as viral myocarditis, children often appear sleepy, poor spirit, fatigue, arrhythmia and other symptoms. (3) Electrolyte disorders: for example, dehydration caused by diarrhea can cause drowsiness, depression and decreased urine output. (4) Endocrine diseases: such as diabetes mellitus, hypothyroidism, etc., there can be fatigue, lethargy, mental depression and other conditions. (5) Craniocerebral diseases: such as cerebral hemorrhage, brain tumors and other diseases, often with poor spirit, lethargy, headache, vomiting and other symptoms. There may be other reasons for your child’s lethargy and lack of spirit, so we suggest that you go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment under the guidance of the doctor.