Ten-year-old girls with small hard lumps in the chest, the common causes may have the following two aspects: 1, if the child has a hard lump in the local chest, in addition to the hard nodules can be touched, the surrounding skin is red and obvious, local pressure pain is obvious, and even nipples have exudate, sometimes may be accompanied by fever, in most cases is acute mastitis, the need for routine anti-infection treatment, oral anti-inflammatory drugs. In addition, local hot compresses can be taken to help reduce swelling as soon as possible, and diet as light and easy to digest food as possible. 2, the girl puberty development starts. At this time, the girl’s breasts can be touched in addition to the movable nucleus in the breast, there may be localized pressure pain, no abnormal redness of the surrounding skin, no other performance can be seen, most of the performance of puberty, you can take the child to the hospital, improve the pelvic ultrasound examination, look at the ovarian follicles, in addition to the child to monitor the bone age to further clarify.