痛苦 (tòng kǔ) is a compound word meaning 'pain' or 'suffering'—both physical and emotional. The first character, 痛 (tòng), means 'ache' or 'sharp pain', often used for bodily discomfort like a headache or injury. The second character, 苦 (kǔ), means 'bitter' or 'hardship', carrying strong connotations of mental or spiritual distress, such as grief, disappointment, or exhaustion. Together, they form a cohesive noun or adjective describing intense, often prolonged, suffering that affects the body, mind, or spirit.

This word appears frequently in literature, medical contexts, and everyday speech when discussing serious hardship—e.g., chronic illness, loss of a loved one, or psychological trauma. It’s more formal and weighty than simpler terms like 疼 (téng, 'to ache') or 难过 (nánguò, 'to feel sad'), and it rarely describes minor discomforts. While it can modify nouns (e.g., 痛苦的经历 'a painful experience'), it most commonly functions as a noun after verbs like 感受 (gǎnshòu, 'to feel') or 经历 (jīnglì, 'to experience').