© 2015 IEEE. The requirements of a Medical Wireless Sensor Networks (MWSN) may vary compared to other networks. The variations could be at different levels i.e. network level, clustering level or security level. This paper looks at the necessary requirements, with particular focus on clustering and routing. It includes an implementation of a MWSN in Contiki operating system using Tmote Sky and openmote technologies. This implementation incorporates a mechanism for the election of a cluster head, and the case of a modified secure routing algorithm. The results are provided with simulation-based, and real world measurements. The paper presents single and collaborative selective forwarding detection and correction with an accuracy check. Additionally, a solution to the problem of malicious nodes dropping control messages has been provided. The uniqueness of the paper resides in the system's capability in detecting and correcting both single and collaborative selective forwarding attacks with 93% and 86% accuracy respectively.