Wireless Body Area Network (WBAN) is a promising technology that is having a significant number of applications in healthcare. Despite having several benefits, WBAN is susceptible to several security attacks, particularly related to the node misbehavior attacks such as sinkhole, wormhole, blackhole, and grayhole attacks. In this research work, the performance of the AODV protocol against wormhole and sinkhole attacks has been analyzed. This comparison-based study has been achieved for the PDR (Packet Delivery Ratio), NRL (Normalized Routing Load), residual energy, packet loss, average throughput, and average end-to-end delay metrics for WBAN with 20 and 50 nodes respectively. The results show that in 20 nodes network the PDR and average throughput of the sinkhole is 32% and 53% more than the wormhole attack, respectively. However, NRL is 36% and the average e2e delay is 63% less than the wormhole attack. In 50 nodes network, the PDR of a sinkhole attack is 26% and the average throughput is 10.7% more than the wormhole attack. Though, NRL and average e2e delays are 41.7% and 78.5% less than the wormhole attack, respectively. Hence, the wormhole attack in either network is more destructive than the sinkhole attack. Based on the simulation results, some solutions against the mentioned attacks have been recommended.