If a breast lump appears in the premenstrual period and is accompanied by pain, and if the lump becomes softer, smaller and the pain disappears after the onset of menstruation, it may be caused by hyperplasia; if a lump appears during lactation and is accompanied by pain, it may be due to milk accumulation and infection; if a lump appears at an older age and is accompanied by pain, it may be a malignant tumor. If the lump appears after menstruation, the size of the lump becomes softer and smaller, and the pain disappears, the pain is considered to be caused by hyperplasia, and if the lump appears during lactation and is accompanied by pain, it is considered to be a combination of milk accumulation and infection. If the lump appears in the premenstrual period and is accompanied by pain, and after the onset of menstruation, the lump becomes softer, smaller in size, and the pain disappears, the pain is considered to be caused by hyperplasia, and if the lump appears during lactation and is accompanied by pain, the lump is considered to be a milk accumulation combined with infection. If the lump is accompanied by pain, we should consider whether it is a malignant tumor, bleeding or pain caused by necrosis, and deal with it.