This document provides an overview of wireless body area networks (WBANs) for health monitoring applications. It discusses the history and components of WBANs, including wearable and implanted sensors, network architecture with intra-body, inter-body and beyond-body communication tiers, and common radio technologies like Bluetooth and Zigbee. It also examines MAC protocols, security requirements, applications, and concludes by discussing the benefits of continuous health monitoring using WBANs.