Advancements in nanotechnology have shown a new paradigm shift in the decision-making and treatment modality for the healthcare world. The unavailability of reliable non-invasive sensors has significantly delayed progress in the field of on-body sensing. The primary aim of this book chapter is to give an overview of the recent developments in non-invasive and implantable nano systems such as wearable and dermal implantable sensors for the continuous monitoring and delivery of therapeutics for the prevention of diseases with high precision and fidelity without affecting the activity of patients. A wide range of implantable and non-invasive nanosystems has been developed for real-time non-invasive monitoring of electrolytes and metabolites in saliva, sweat, and tears as indicators of personal health status. This chapter discusses the physiological parameters and diseases that could be managed by employing the rapidly progressing implantable and non-invasive nano systems and the latest interventions that have been researched to date. Furthermore, it focuses on the technical challenges, regulatory issues, and future trends in non-invasive health monitoring.