体质 (tǐ zhì) literally combines 体 (tǐ), meaning 'body' or 'physical form', and 质 (zhì), meaning 'substance', 'nature', or 'quality'. Together, they refer to a person’s inherent physical constitution — including factors like strength, stamina, metabolic tendency, susceptibility to illness, and response to climate or diet. In traditional Chinese medicine (TCM), 体质 is a foundational concept used to classify individuals into types (e.g., yin-deficient, damp-heat, qi-deficient) that guide personalized health advice.

The term is commonly used in medical, wellness, and everyday contexts — for instance, when discussing why someone feels cold easily, recovers slowly from colds, or benefits more from certain foods or exercises. Unlike the Western biomedical term 'health status', 体质 emphasizes innate, long-term physiological patterns rather than temporary conditions. It reflects both genetic predisposition and lifelong lifestyle influences, making it central to preventive care and holistic self-awareness in Chinese culture.