Continuous, remote monitoring of patients' healthcare condition, as this can be reflected by crucial vital signs supervision, is a key demand in modern healthcare provision. Towards the accomplishment of this requirement, the traditional solution of cabled sensors appears to have clear limitations and this is one of the ultimate causes of the proliferation of wireless medical sensor networks during last years. The modern trend towards this direction is the formulation of patient Personal Area Networks (pPANs), consisting of a wireless infrastructure of medical sensors, attached to patient's body, which lays the path for incessant telemonitoring of the person in mind, without discomforting them. The nature of data that these networks are set to handle, as well as the particular demands that patient telemonitoring services raise, necessitate for a thorough analysis of the design requirements of pPAN communication protocols, in order to outflank possible disadvantages appearing in protocols for different types of wireless sensor networks, without putting aside simplicity and feasibility factors. In the context of this paper, we intend to outline the most important requirements and design issues of a pPAN communication protocol, having as compass the main attributes of the most commonly used medical sensors and the typical functionality of these networks.