Wireless Body Area Network(WBAN) is a novel promising sub-field of wireless sensor network. A key application of Wireless Body Area Network is health monitoring. Wireless sensors are placed on the human body or implanted in the body to observe essential signs like blood pressure, body temperature, heart rate, glucose level etc. Use of Wireless Body Area Network technology to monitor health parameters significantly reduces the expenditures of patient in hospital. In this paper we study the different tools and techniques which are useful in wireless body area network.