Precision health monitoring systems represent a transformative approach to collecting and analyzing physiological and biochemical data in real time. By leveraging integrated bioelectronics encompassing advanced sensors, low-power analog front ends, on-chip computational units, and embedded wireless communication interfaces, these systems enable continuous, non-invasive monitoring in compact, user-friendly devices. This chapter provides a comprehensive overview of the fundamental building blocks of precision health monitoring integrated bioelectronics, highlighting the unique challenges and circuit-level solutions required for high-fidelity electrophysiological and electrochemical signal acquisition. Key considerations for signal integrity, noise reduction, and energy efficiency are detailed, with discussions on front-end amplification techniques for weak biopotential signals, robust potentiostat designs for electrochemical sensing, and the selection and implementation of energy-efficient analog-to-digital converter architectures. The chapter also examines the integration of emerging technologies, such as edge artificial intelligence and multi-modal sensor fusion, which further enhance system performance and functionality. These innovations, combined with advanced packaging and form factors, pave the way for the next generation of mobile, wearable, and precision health monitoring systems for personalized and preventive care.