This chapter explores the pivotal role of microstrip patch antennas in wearable health monitoring systems, focusing on their integration within wireless communication systems operating in the 2.4–5.8 GHz range. It begins with an introduction to wearable antennas and their significance in real-time health monitoring, particularly for body-worn applications. Emphasis is placed on critical design considerations including antenna miniaturization, radiation efficiency, and consistent performance despite detuning effects caused by proximity to the human body. A comprehensive overview of electronic solid-state sources and their compatibility with wearable devices is provided to guide system-level integration. The chapter presents a detailed case study on designing a microstrip patch antenna for a fitness tracker, illustrating practical implementation strategies and performance optimization techniques. It highlights advanced methods for improving antenna radiation patterns and efficiency, along with materials suited for biocompatibility and flexibility. Furthermore, it addresses key challenges in ensuring wireless communication within and around the human body and mitigating interference in dense RF environments. Solutions such as frequency hopping, spectrum sharing, filtering, isolation, and electromagnetic shielding are examined to enhance coexistence with other wireless systems. Finally, the chapter identifies open research challenges, paving the way for future innovations in wearable biomedical antenna technologies.