The word 心血 (xīnxuè) is a compound formed by combining the characters for 心 (xīn), meaning "heart" or "mind", and 血 (xuè), meaning "blood". Together, they create a powerful metaphor where "heart-blood" symbolizes the vital essence of one's life force, spirit, and energy. In usage, it refers to the immense mental and physical effort, careful thought, and profound dedication someone pours into a task or creation, much like one's very lifeblood, implying that the work is a product of deep personal investment and sacrifice.