Swelling and pain at the areola in boys can be caused by trauma, breast enlargement, gynecomastia and so on. 1. Trauma: If the patient is bruised, scratched, or there is excessive friction, it will lead to swelling and pain at the areola of boys. 2. Mammary hyperplasia: When the quality and quantity of the patient’s mammary sex hormone receptors are abnormal, causing different degrees of hyperplasia in various parts of the mammary gland, it may lead to swelling and pain at the areola of boys, accompanied by mammary nodules or lumps. 3. Gynecomastia: If the androgen in the patient’s body decreases or the proportion of androgen is out of proportion, the patient may have the phenomenon of swelling and pain in the areola, accompanied by breast lumps, nipple overflow and other symptoms. In addition to mastitis, breast cysts may also appear similar clinical manifestations, it is recommended that the patient to the regular hospital in a timely manner, in the doctor’s diagnosis, according to the patient’s specific condition performance, to take targeted treatment.