In this paper, we explore and discuss the data security issues in a real-time remote patient health monitoring system, called the Personal Health Data Management System (PHDMS). The health monitoring system examined for this study consists of multiple wireless sensors, central data coordinator called the Wireless Intelligent Personal Communication Node (W-iPCN), an Android smartphone, and a remotely located central medical server. The PHDMS transmits raw sensor data from the W-iPCN to the Android smartphone using the Bluetooth connection. In addition, the system transmits raw sensor data using the Wi-Fi or cellular broadband connection between the Android smartphone and the central medical server. As a case study, we present a security protection scheme to encrypt and decrypt raw sensor data using multiple cryptologic algorithms. We applied this security protection scheme on the W-iPCN, Android smartphone and the central medical server to test their ability to process and transmit sensor data in real-time. This security assessment aims to observe the performance of data encryption and decryption, and real-time feasibility to remotely monitor patients' health.