The healthcare sector is rapidly changing its administrative and medical processes due to the influence of AI systems. AI-driven technologies are making significant progress in early detection and diagnosis, aiming to enhance healthcare services and improve human life quality. As a result, AI is utilised for diagnosing illnesses, suggesting treatments, and ensuring adherence. Despite the fragmented literature on the topic, AI technology is attracting attention as a promising solution to healthcare challenges. This paper presents a systematic review of peer-reviewed literature from January 2020 to December 2024, synthesizing advancements and challenges of AI applications in healthcare.