The Chinese word "疼痛" is formed by combining two characters, 疼 and 痛, both of which individually convey the meaning of "pain" or "ache", creating a compound that reinforces and intensifies the concept through their synonymous pairing. Graphically, both characters share the "疒" (sickness) radical, which visually anchors them to the domain of physical discomfort or illness, thereby enhancing the word's associative meaning. This structure exemplifies a common Chinese word-formation strategy where semantic repetition is used to emphasize a unified idea, resulting in a term that vividly encapsulates the sensation of pain.