The bulge of the sternum parallel to the nipple may be due to physiologic factors such as fat accumulation, pronounced raphe, or pathologic causes such as lipomas or lumps. 1. Physiological factors (1) Adipose accumulation: In obese patients, a large amount of adipose tissue is present in the sternal region, which forms a kind of fat protruding from the surface of the body. (2) Obvious raphe: In thin patients, the raphe on the sternum will be obviously raised, which is a normal phenomenon, and it will look like the sternum is raised parallel to the nipple. 2. Pathologic causes (1) Lipoma: It is a common benign soft tissue tumor, composed of mature fat cells, and can appear parallel to the sternum and nipple. (2) Lumps: are nodules or swellings on the surface of the skin that can also cause what appears to be a sterno-nipple bump. If the symptoms of a breastbone to nipple bump persist without relief, it is necessary to seek medical treatment to identify the cause.