The bone in the middle of the chest is medically called the sternum. From top to bottom, the sternum is divided into three parts: the sternal stalk, the sternal body, and the saber, where the sternal stalk, and the middle part of the sternal body, protrude forward at the junction, medically known as the sternal horn. It is a normal anatomical structure that protrudes forward normally, but in pathological conditions of certain diseases, it can also cause it to protrude forward, and it is very pronounced in all parts of the sternum. For example, neonatal vitamin D deficiency rickets, which occurs with funnel chest, chicken chest, sternal tumors, and sternal fractures, among others, can manifest as sternal protrusion. So the protruding sternum, depending on its different conditions, to determine whether it is normal. If it is normal, it does not need to be dealt with. If it is caused by a disease, it needs to be promptly seen by the thoracic surgery department of the hospital and given different symptomatic treatments according to different diseases.