Large language models (LLMs) represented by ChatGPT are one of the most prominent research topics in artificial intelligence (AI) today. They are considered critical technological means for driving revolutionary transformations across traditional industries, providing substantial momentum for industrial innovation and upgrading. As a key domain of long-term exploration and application for AI technologies, the healthcare field is currently confronted with accelerated aging of the population, insufficient medical resource supply, and tense physician-patient relationships. Under this background, AI is regarded as the most promising solution to thoroughly solving these conflicts and problems, especially the LLMs represented by ChatGPT, which offer people a glimpse of hope. This study first briefly reviews the development of natural language processing (NLP) technologies, followed by a systematic introduction of the historical development background and technical evolution trajectory of the GPT-series LLMs. By combining the practical demands and current status of the healthcare industry, it discusses the application scenarios and cases of LLMs represented by ChatGPT in this field by category. Finally, this study conducts an in-depth analysis of the inherent limitations of LLMs and challenges encountered during the large-scale deployment, implementation, and utilization, with some targeted solutions and ideas provided.