In wireless sensor networks, congestion occurs when the traffic load being offered exceeds the available capacity of sensor nodes. In most applications, every sensor node will send the event it has sensed to a sink node. This operation makes the sensors closer to the sink, resulting in congestion. Congestion may cause packets loss, lower network throughput and sensor energy waste. To address this challenge, there is a proposal for a distributed algorithm that mitigates congestion and allocates appropriate source rate to a sink node for sensor networks. The proposed algorithm is a hybrid congestion control protocol that considers not only the packets delivery rate but also retains the buffer size of each node. The proposed protocol may avoid packets drop due to traffic congestion and improve the network throughput. The simulation results show that the performance of the proposed protocol is better than the previous works.