The bulge below the heart socket of young children may be caused by the protrusion of the raphe, lipoma, rickets and so on. 1. Protruding raphe: If the bulge is located directly below the sternum, it is a normal physiological phenomenon that the raphe at the lower end of the sternum is protruding. 2. Lipoma: due to heredity, abnormal lipid metabolism, chronic inflammation and other reasons, resulting in lipoma, most of the body parts of one or more lumps under the skin, forming a bulge. 3. Rickets: due to insufficient intake of vitamin D, short sun exposure time and other reasons, the lack of vitamin D, thus causing rickets, when the condition worsens, there will be a square skull, cranial softening, chicken chest and other symptoms, thus causing the phenomenon of the bulge below the heart socket. There may be other reasons for the bulging of the lower part of the fossa in young children, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment under the guidance of the doctor.