Hard lumps in breasts during breastfeeding are considered to be caused by milk stagnation. If there is enough milk, or even a large amount, which the baby can’t finish, or if the milk ducts are too thin or not smooth, it is easy to cause milk accumulation and hard lumps, it is recommended to use a breast pump to suck out the remaining milk after each time the baby finishes the milk. If you have hard lumps in your breasts, you can use a warm towel to apply hot compresses or gentle massage to relieve the lumps, but do not exert too much force so as not to affect the physiological function of the milk ducts. If the symptoms are serious, you need to go to the hospital for ultrasound examination to rule out the occurrence of acute mastitis. Wear cotton, loose corsets, avoid wearing tight corsets, so as not to cause excessive compression of the breasts, and mood should also pay attention to keep cheerful, optimistic and happy. If the hard lumps in the breast do not disappear through the above treatment, you need to go to the hospital in time to exclude other possible breast diseases.