The girl has 9 days and 9 weeks old, the chest has one side of the bulge, mostly considered a normal phenomenon, of course, can not be ruled out pathological phenomena, the specific also depends on the child’s clinical manifestations. 1. Normal phenomenon: the girl is still 9 days 9 weeks old, there is a side of the chest bump, may be a normal physiological phenomenon, and the development of the girl’s secondary sexual characteristics. 2. Pathological phenomenon: in addition to the child’s chest bulge, there may be some other accompanying symptoms, such as intracranial space-occupying lesions due to the child’s development, most of the children will also be accompanied by dizziness, headache, vision loss and other symptoms. These are abnormal and require prompt medical attention. The girl is 9 days and 9 weeks old and has a side of the chest protruding, parents are advised to take the child to the pediatrics or endocrinology department of the hospital to check it out, and if necessary, should intervene under the guidance of the doctor, so as not to affect the child’s normal height and development in the future.