Primary Ciliary Dyskinesias (PCDs) are a group of rare genetic disorders that affect the cilia, which are tiny hair-like structures found on the surface of cells in our respiratory tract and other organs. These cilia play a crucial role in clearing mucus and foreign particles from our airways, among other functions. PCDs are sometimes referred to as immotile cilia syndrome or ciliary dyskinesia. Other synonyms include Kartagener syndrome, due to the association with situs inversus (where internal organs are mirrored from their usual positions), and primary ciliary dyskinesia with respiratory manifestations. Despite the different names, all these terms describe a similar condition characterized by impaired ciliary function.