Introduction.- Features of wireless body sensor networks.- Emerging trends of WBSN and the present health care system.- Technology, protocols and use cases of wireless WBSN.- Literature survey on various health monitoring system.- Wireless communication protocols in health monitoring.- WBSN challenges and their solutions.- Communication protocols of implanted, wearable and nano body sensor networks.- Interference and channel allocation.- Energy harvesting methodologies and experimentation.- Reliability analysis and fault tolerant architecture for WBSN.- Buffer management in delay tolerant and delay in tolerant monitoring.- Handling network failure during critical duration.- Trust models and digital signature concepts in wearable nodes.- Animal health monitoring system.- Physiological sensor design.- Factors affecting Sensor reusability, Sensing time and sensed state to initial state.- Conclusion.