M-health is becoming a major technological trend for ambulatory and prolonged physiological monitoring. It has the potential to shift the paradigm of health care from reactive to proactive, from disease management to disease prevention. The widespread use of communication and information technologies facilitates the delivery of medical services at a distance, which is known as telemedicine. New approaches have also forced changes in clinical practices, the most notable being the introduction of electronic medical records and information and communications technology. This new paradigm is known as eHealth. Recent developments in sensors, wearable computing, and ubiquitous communications have the potential of providing clinicians and users with tools and environments to gather physiological data over extended periods of time. This emerging concept is known as m (mobile)-health and represents the evolution of eHealth systems from traditional desktop telemedicine platforms to wireless and mobile configurations. he main enabling technological trends for m-health systems include: increased communication and computation capabilities of cell phones; the new generation of power-efficient processors and communication controllers; revolutionary changes in microelectromechanical systems (MEMSs) and nano-sensor technologies enabling embedded and implanted biomedical sensors in frequently used objects in homes and offices. It outlines enabling technologies and the taxonomy of m-health applications and introduces the ultimate concept in unobtrusive system organization for ''anytime, anywhere'' monitoring-wireless body area networks (WBANs) of intelligent wireless sensors. One of the most promising application domains is health monitoring, and within health care, WBANs in particular are emerging as promising enabling technologies to implement m-health.