The healthcare system is undergoing rapid transformation as national policies increase patient access, reward positive health outcomes, and push for an end to the current era of episodic care. Advances in health sensors are rapidly moving diagnostic and monitoring capabilities into consumer products, enabling new care models. Although hospitals and health care providers have been slow to embrace novel health technologies, such innovations may help meet mounting pressure to provide timely, high quality, and low-cost care to large populations. This leading edge perspective focuses on the quantified-self movement and highlights the opportunities and challenges for patients, providers, and researchers.