Excessive daily sleepiness associated with obstructive sleep apnea is a multifaceted complaint that usually involves disabling symptoms. Despite being a common complaint, best practice regarding the management of patients is not well defined, and failure to recognize the severity of the effects of symptoms on quality of life results in underdiagnosis, preventing patients from receiving adequate treatment. 'Fast Facts: Excessive Daily Sleepiness Associated with Obstructive Sleep Apnea' discusses the difficulties in formulating a single definition of excessive daily sleepiness that appropriately considers the experiences and features of daytime sleepiness, alongside an up-to-date overview of how to accurately assess patients, and ensure effective management and support. Table of Contents: • Epidemiology and etiology • Clinical features and diagnosis • Management • Patient impact and support