Over the past few years many medical professionals have shifted their focus to ubiquitous health monitoring systems. With continuous advancements in both bio-medical and information technologies, such futuristic monitoring systems have become a present reality. When intermixed with ubiquitous computing, a mobile health monitoring system provides unrestrained potential and innumerable applications. This research aims to improve upon and advance beyond modern medical monitoring systems by incorporating ontology-based reasoning to make the system independent and automated. In this paper, we present the main features of our ubiquitous mobile health monitoring system, its hardware and software design, and potential applications.