Wireless body area network (WBAN) is targeted to monitor the physiological parameters of human being. This network basically consists of many sensors to sense the parameters. The wearable body sensor unit is equipped with the transmitter, central processing unit (gateway) and the receiver. The gateway devices are used to connect wearable devices on a human body to the internet. Medical professionals can access the patient data by using the internet, independent of patient location. The major problem in this type of network is to increase the lifetime of the sensors as well as the performance of the network. In order to increase the lifetime of the network, the energy consumption of the sensors and bit error rate is reduced by using efficient error correcting codes. In this paper, to achieve the reliable data transmission, Raptor code, a type fountain code is used for encoding in order to increase WBAN efficiency by detecting and correcting the errors. The total energy consumed to transmit the sensed encoded bits is analyzed using Raptor code. The energy efficiency of the sensor, as well as the network, is increased by using Raptor code when compared to other conventional coding technique.