Chest pain has a variety of sources, and virtually any structure in the chest can cause pain. This includes the lungs, the ribs, the chest wall muscles, the diaphragm, and the joints between the ribs and breastbone. Injury, infection, or irritation to any of these tissues can be responsible for chest pain.
Occasionally, pain can be referred from another area (e.g., the abdomen). Chest pain may also be a manifestation of stress or anxiety. Rarely, the heart is the source of chest pain in children.