In this study, we discuss the recent trends in treating obstructive sleep apnea in details with special emphasis on the pathophysiology, as well as both recent and old modalities for diagnosing it. In the pathophysiology, we present the craniofacial abnormalities, upper airway shape, nasal pathologies and other contributing factors. The physical assessment of the patient’s upper airway as well as the diagnostic tests (e.g. Cephalometry, CT, MRI, Sleep Naso-endoscopy) are then discussed. Finally, treatment options are discussed in details ; whether non-surgical (e.g. CPAP and oral appliances) or surgical operations for the nose, palate, oropharynx and hypopharynx following a generally accepted staged surgical protocol.