Infants cry until their faces turn purple, purple manifestation is due to the lack of oxygen caused by infants crying, this situation can be caused by physiological causes and pathological causes. If it is physiological, with the growing age, this symptom will slowly disappear, do not need to do special treatment. The most common pathologic clinical cause is congenital heart disease in children, and when these children have an attack, they can knock on the back and stimulate the soles of the feet, and the symptoms will be relieved. If frequent seizures, or even hypoxia leading to convulsions, it is recommended to go to the hospital for further examination to rule out any other causes of hypoxia.