It is believed in Chinese medicine that this disease belongs to the category of "Breast Carbuncle". The problem occurring during lactation is termed "external breast abscess" and the problem happening during pregnancy is termed "internal breast abscess". This disease is mostly related to the patient's emotional problem and stagnation of the liver qi or caused by accumulation of heat due to improper food intake after delivery, leading to obstruction of the collaterals in the breasts and suppuration by heat resulted from accumulation of milk. Besides, this disease can also be caused by deformity of the puerpera's breasts, hesitant lactation, or by suppuration related to invasion of pathogenic factors due to rupture of the nipples.