疼痛，尤其是慢性疼痛，不仅给人们带来身体上的不适，而且对人的精神、心理和体质等产生不同程度的负面影响。疼痛作为临床上最常见的症状之一，是影响人类健康的一个世界性难题。其中，急性疼痛到慢性疼痛的转变机制仍不清楚，且缺乏监测疼痛慢性化的可靠指标。考虑到疼痛慢性化进程所伴随的一系列的病理学、心理学和生理学的改变，本项目将综合多方面因素（如躯体感觉系统功能、心理状态、下丘脑-垂体-肾上腺皮质轴功能、脑结构与功能等），采用纵向研究，(1)探讨由急性疼痛发展为慢性疼痛过程中各因素的动态变化性，(2)研究慢性疼痛发展的机制及理论模型，(3)确定疼痛慢性化特异性生物指标，实现疼痛慢性化的有效监测。该项目的预期成果既可预测急性疼痛患者发展为慢性疼痛的风险性，为早期干预治疗提供指导，又可评估慢性疼痛得以持续的原因，为临床镇痛药物的使用或治疗方法的确定提供指导，最终帮助缓解或去除患者的痛苦，提高患者的生活质量。

Pain, especially chronic pain, not only leads to somatic discomfort, but also adversely affects the health of humans in mental, psychological, and physical aspects. Pain is one of the most common clinical symptoms, and has been considered as a worldwide healthcare problem. Importantly, the mechanism of transition from acute to chronic pain remains unknown. Besides, there is a lack of reliable index for the monitoring of pain chronification. Considering that pain chronification is accompanied by a chain of alterations in the aspects of pathology, psychology, and physiology, this project will combine multiple factors (e.g., function of somatosensory system, psychological state, the hypothalamic-pituitary-adrenal axis function, as well as the brain structure and function) and use a longitudinal study (1) to investigate their dynamic changes in the transition from acute to chronic pain, (2) to explore the mechanism and theoretical models of pain chronification, and (3) to determine the specific biomarkers of pain chronification for the effective detection of the transition from acute to chronic pain. The expected outcomes of this study can be applied in clinical practice, as they can be used to predict the probability of the transition from acute to chronic pain in patients so that guidance for early intervention could be provided. Also, they can be used to evaluate the causes of chronic pain to guide the use of analgesic drugs and treatment strategies, eventually, helping relieve or eliminate pain for patients and improve their quality of life.