IoT is the new paradigm that changes human life. IoT increases the quality of life in every aspect and connects every device to each other. Smart cities have emerged with devices that connect to each other and automate decisions in each part of the city. Healthcare systems are one of the important applications in smart cities that are gaining a lot of attention. Storage and speed of computation is one of the main concerns in healthcare systems. Fog computing provides more efficient healthcare systems. In this chapter, we review fog computing concepts and review the challenges and features that are provided with the aid of fog computing.