ABSTRACT
Sleep disordered breathing (SDB) is a clinical syndrome resulting from obstruction of the upper airway during sleep. Clearly, the syndrome is not the result of any single site and cause of obstruction, as many potential sites and reasons for obstruction have been identified. In addition, since the primary treatment for SDB is continuous positive airway pressure (CPAP), the precise site and cause of obstruction is not always crucial. Historically, descriptions of upper airway abnormalities were qualitative in nature; quantitative standardized descriptions were not previously available.
