The advent of self-powered smart textiles for wearable devices is garnering considerable attention in the domain of human health monitoring. This paper reviews recent progress in the emerging field of self-powered smart textiles, with a particular focus on systems integrated with textile substrates. It first introduces the operating principles of five self-powered technologies, including piezoelectric, triboelectric, photovoltaic, thermoelectric, and moisture-electric mechanisms, and then analyzes recent advances in material selection and device development. Subsequently, the focus shifts to the practical applications of these self-powered textile substrates in the monitoring of physiological parameters, including heart rate, pulse, respiration, and body temperature. Furthermore, this paper also explores the potential impacts of these applications in the field of rehabilitation and assisted rehabilitation, specifically covering key dimensions such as practicality, integration level, and durability. Finally, the paper assesses the prospective applications of self-powered smart textiles in sports health monitoring, chronic disease management, and geriatric care, underscoring their significance in advancing personalised medicine and smart health management, and offers insights into the integration of AI with self-powered technologies, industrial development, and data security.