The Anatomy of a Personal Health

Health is a fundamental pillar of human wellness, and the rapid advancements in large language models

(LLMs) have driven the development of a new generation of health agents. However, the application

of health agents to fulfill the diverse needs of individuals in daily health settings is underexplored.

In this work, we aim to build a comprehensive personal health agent that is able to reason about

multimodal personal health data from everyday consumer wellness devices and medical records and

provide personalized health recommendations. To understand end-users’ needs when interacting

with such an assistant, we conducted an in-depth analysis of web search and health forum queries,

alongside qualitative insights from users and health experts gathered through a user-centered design

process. Based on these findings, we identified three major skill categories to fulfill consumer health

needs, each of which is supported by a specialist sub-agent in our system: (1) a data science agent

that analyzes personal time-series wearable and medical record data, incorporating population-level

statistics to provide contextualized numerical health insights, (2) a health domain expert agent that

integrates users’ health and contextual data to generate accurate, personalized insights based on health

domain knowledge, and (3) a health coach agent that synthesizes data insights, drives multi-turn

user interactions and interactive goal setting, guiding users using a specified psychological strategy

and tracking users’ progress. Furthermore, we propose and develop Personal Health Agent (PHA), a

multi-agent framework that enables dynamic, personalized interactions to address individual health

needs. To evaluate each sub-agent and the multi-agent system, we conducted automated and human

evaluations across 10 benchmark tasks, involving more than 7,000 annotations and 1,100 hours of effort

from health experts and end-users. Our work represents the most comprehensive evaluation of a health

agent to date and establishes a strong foundation towards the futuristic vision of a personal health agent

accessible to everyone.#