Common causes of breastfeeding underarm bumps are paratesticular lymph nodes and sebaceous cysts. Massage, violent stimulation and hot water compresses should be avoided during breastfeeding. If possible, localized cold compresses can be applied to relieve pain, magnesium sulphate can be applied as a wet compress, and potato chips can be placed to reduce edema. If both breasts are producing enough milk, you should avoid eating milk-producing foods, such as crucian carp soup, pig’s trotters soup, and so on. For patients with lymphadenitis under the armpit or sebaceous cyst infection, in this case, it is generally recommended to apply sensitive antibacterial drugs for infusion treatment, the effect is faster. And it does not affect breastfeeding. Cephalosporins and penicillins are safer. Even if these drugs are secreted through breast milk, they generally do not have a significant effect on the baby. Penicillin is the recommended drug of choice.