The integration of Artificial Intelligence (AI) and the Internet of Things (IoT) in healthcare is transforming chronic disease management and pandemic response, particularly for vulnerable populations such as the elderly and those with multiple chronic conditions. This review systematically examines the current applications of AI and IoT technologies in managing chronic diseases like diabetes, cardiovascular disease, and chronic obstructive pulmonary disease (COPD), alongside their role in enhancing healthcare response during the COVID-19 pandemic. Key findings demonstrate significant improvements in patient outcomes, including enhanced glycemic control in diabetes management, early detection of cardiovascular anomalies, and a reduction in hospital admissions for chronic disease patients through AI-enabled remote monitoring. Despite these advancements, challenges remain, including data security, algorithmic bias, and the high cost of implementing AI and IoT systems. This review explores future directions for overcoming these obstacles, emphasizing the potential of multi-dimensional data integration, real-time predictive analytics, and personalized AI models to further revolutionize healthcare. Additionally, the accompanying Graphic Abstract visually illustrates how AI-driven insights, generated from IoT-enabled devices, are transforming healthcare delivery by facilitating real-time monitoring, personalized interventions, and proactive patient care. The article concludes with recommendations for addressing the technological, ethical, and regulatory challenges that must be overcome to fully realize the potential of AI and IoT in healthcare.