The word 伤心 is formed through a direct and vivid conceptual fusion: it takes the idea of physical injury or harm (伤) and applies it to the core emotional center, the heart (心). This creates an immediate, visceral image of the heart itself being wounded, translating the abstract feeling of deep sorrow or grief into a concrete, almost physical sensation of damage at one's very core. It is a metaphorical embodiment of emotional pain.