Pre-dose physical examination: electrocardiogram, cardiac ultrasound, routine blood tests. Exclude arrhythmia, severe conduction block, congenital heart disease and other disorders; exclude bronchitis, pneumonia, asthma. Contraindications: Propranolol, a traditional drug that has been used for decades, is indicated with contraindications including cardiac lesions (conduction block), airway sensitivity disorders, ventilation difficulties, or other pulmonary disorders. Drug specifications: 100 tablets/bottle, 10mg/tablet; price 2.5 to 3.5 RMB/bottle. Need to be sealed and stored, valid for 3 years. Dosage: 1~3mg/kg, commonly 2mg/kg, divided into 2~3 oral doses, recommended to be divided into 2 doses. Dosage: 10-15 minutes after breastfeeding, crush the tablet, put it in a spoon, dissolve it in 10mL of sugar water or milk water (milk powder) and pour it into the mouth at once. If the infant does not cooperate in spitting out the medicine, try to take a refill according to the dosage. Propranolol should be given during the day after eating, at least once in 4 hours for infants <6 weeks, once in 5 hours for infants 6 weeks to 4 months, and once in 6-8 hours for infants 4 months old. The drug can be taken after eating to avoid hypoglycemia. The plasma half-life (plasma half-life) is 3-6 h after oral administration. Note to parents: diarrhea, hypotension, bradycardia, hypoglycemia, tracheospasm and other complications may occur after taking the drug. In case of severe diarrhea, the drug needs to be stopped and taken again after adaptation. If tracheal or bronchospasm or asthma is induced, the drug needs to be discontinued immediately, and the drug cannot be continued. Hypotension, bradycardia, and hypoglycemia generally have no subjective symptoms and do not require treatment. Other special cases need to be reviewed at any time. Vaccinations can be received normally during the treatment period. Adverse effects: Common adverse effects include hypoglycemia, hypotension, slowed heart rate, diarrhea, sleep changes, and asthma attacks, while others such as chills in the hands and feet, irritability, sweating, constipation, convulsions, lethargy, and hypothermia are rare. They usually occur at the beginning of treatment and most of them do not require special treatment or only symptomatic treatment and can recover after a few days without affecting the continuation of treatment. There was no significant difference in blood glucose, liver and kidney function and thyroid function before and after treatment. The efficacy of propranolol on proliferative hemangioma in infants and children is significantly better than that of glucocorticoids. From the current clinical treatment effect, coupled with the analysis of the detailed assessment of safety and side effects established by propranolol for the treatment of cardiovascular diseases in infants and children over the past 40 years, propranolol is a safer and more convenient drug for the treatment of hemangioma in infants and children. Post-treatment response: 1 week after oral administration of propranolol, the tumors began to lighten in color and shrink and soften. After 3 months of treatment, most of the tumors shrank significantly. By 1 year of age, the tumor is largely receding, and capillary dilatation may remain on the surface. Significant changes are seen in the first 8 weeks and at 6 months of age, with a >20% decrease in heart rate being an early indicator of onset of action. Duration of treatment: The effect of propranolol on angiodysplasia is most pronounced in the first week, after which the rate of improvement is slow and sometimes there is a period of stagnations. The reason for this may be the early presumed vasoconstrictive effect, while the effect of the drug on molecular markers of hemangioma is not clinically evident. However, drug therapy must be continued for at least 6 months, as premature discontinuation can lead to rebound. Discontinuation criteria: complete regression of the hemangioma, or age over 1 year and end of the proliferative phase of the hemangioma. Discontinuation method: halve the number of times in the first 2 weeks, halve the dose in the second 2 weeks and stop the medication. Observe for 1 month, if no rebound, complete discontinuation; if rebound, continue medication for 1 month or longer according to the original regimen. Further studies: propranolol oral solution for easy use in infants and children, propranolol topical rub, propranolol mechanism of action, long-term adverse effects (e.g., whether it affects mental development), etc.