The normal heart is located on the left side of the chest, but in some cases of abnormal development or certain diseases, the heart may be located on the right side. The heart sits between the lungs and above the diaphragm. Normally, most of the heart is located on the left side of the chest cavity, i.e., to the left of the midline of the chest, and about 1/3 is located on the right side of the midline of the chest. The anterior aspect of the heart is directly in front of the body of the sternum and the cartilages of the 2nd to 6th ribs; the posterior aspect is flat against the 5th to 8th thoracic vertebrae. Some people may present with the heart located mostly on the right side of the chest. For example, the heart is completely right-sided due to developmental anomalies, which may be accompanied by inversion of the abdominal visceral organs; or the heart is right-sided and the anatomic position of the heart is not completely altered. In addition, the heart may be right-sided in some patients with lung and pleural lesions. It is recommended to consult a doctor for standardized diagnosis and treatment if necessary.