Central sleep apnoea is a condition that is characterized by apnoeas during sleep that are associated with a lack of ventilatory effort. The pathogenesis of central sleep apnoea is complex. This chapter attempts to simplify the complexities inherent in the pathogenesis of central sleep apnoea and thereby provides a framework for the diagnosis of the conditions associated with it. Both hypoventilation-related central sleep apnea and hyperventilation-related central sleep apnea have been considered with special attention to the more prevalent causes of these conditions.