Google is adding a feature to Fitbit that lets users upload medical records — including lab results, medications, and visit history — for use by its AI-powered personal health coach. The coach can then provide personalized responses to health questions based on this data combined with lifestyle patterns tracked by the device. Google states the data won't be used for ads and users retain control, but hasn't clarified whether records are stored on-device or on servers. The company acknowledges LLM hallucination risks and says it invests in validation processes. Additional updates include continuous glucose monitor integration and improved sleep staging accuracy.