Artificial intelligence (AI) has emerged as a powerful tool with the potential to transform various aspects of healthcare. Over the past five years, Google Health has been at the forefront of developing and implementing AI-driven solutions to address numerous challenges in the healthcare industry. This paper presents a comprehensive review of Google Health's progress in harnessing AI to improve healthcare outcomes, with a particular emphasis on their latest conversational AI systems, MedPALM and MedPALM 2, and the potential applications and limitations of these systems. The review begins with an overview of AI's impact on healthcare, highlighting the numerous applications where AI has proven to be beneficial in augmenting the abilities of healthcare professionals and enabling the discovery of new medical knowledge. This is followed by an in-depth analysis of Google Health's key AI innovations, including advancements in breast cancer detection, skin condition identification, genomic sequencing, and the discovery of a tissue morphology feature that predicts colorectal cancer patient survival. The paper then delves into the development, tuning, and performance of MedPALM, a large language model designed to provide high-quality and authoritative answers to medical questions. MedPALM's achievements in surpassing the pass mark on U.S. medical licensing exams are discussed, along with an examination of the evaluation process of MedPALM's answers in comparison to real clinicians. Building on the success of MedPALM, the paper introduces MedPALM 2, a more advanced and improved AI system that boasts impressive performance on medical exam benchmarks, including Indian medical exams. The potential real-world applications and role of MedPALM 2 as a building block for advanced natural language processing in healthcare are explored, emphasizing the tremendous potential of this technology in the field. Lastly, the review addresses the challenges and limitations of AI in healthcare, including the importance of empathy, compassion, addressing bias, and ethical considerations. The paper stresses the need for responsible innovation and the inclusion of diverse experiences, perspectives, and expertise when developing AI systems for healthcare applications. To wrap up, this paper delves deep into Google Health's AI-driven advances in healthcare and its vast potential to transform the sector. However, we must not forget that significant obstacles remain before we can responsibly deploy these technologies ethically.