There are three main types of sleep-disordered breathing which are manifested in sleep apnea. Discovering the specific differences between them can help you recognise how best to treat your patients. Obstructive sleep apnea (OSA) Central sleep apnea (CSA) Complex sleep apnea OSA OSA is a common disorder characterised by repetitive upper airway collapse during sleep resulting in apneas (cessation of airflow) and hypopneas (reduced airflow)1. The primary indications of upper airway obstruction are: lack of muscle tone during sleep excess tissue in the upper airway the structure of the upper airway and jaw OSA determined by polysomnography is highly prevalent, affecting 25% of men and 10% of women in the United States although most are asymptomatic.2 Central sleep apnea (CSA) CSA is clinically defined by a lack of drive to breathe during sleep, resulting in repetitive periods of insufficient ventilation leading to compromised gas exchange, in contrast to OSA where