Disease diagnosis is the systematic process of identifying a specific disease, condition, or injury based on its characteristic signs, symptoms, and other medical evidence. As a research field and academic concept, it investigates the methodologies, data analysis techniques, and discovery of reliable indicators (such as biomarkers and imaging features) for accurately distinguishing pathological states. Its key characteristics involve the integration and interpretation of diverse clinical and biological data, aiming for high accuracy, reliability, and timeliness, and its significance lies in enabling effective medical intervention, predicting prognosis, and advancing medical understanding of diseases.