Obstructive sleep apnea is due to the collapse of the upper airway during sleep. These soft tissues collapse due to negative pressure within the upper airway that lead to complete or partial obstruction of the upper airway causing cessation of breathing, resulting in increased sympathetic activity, increased blood pressure, and hypoxemia. Collapse of the upper airway is often multilevel, at the level of the velopharynx, the base of tongue, and/or the lateral pharyngeal walls. Many patients with obstructive sleep apnea (OSA) have bulky thick lateral pharyngeal walls that contribute to the collapse and obstruction of the upper airway in these patients. These areas of collapse should be addressed, if one is aiming to relieve the patient of the apneas; hence, upper airway evaluation is crucial in the assessment of the anatomical site of obstruction. This lateral wall collapse can also be documented with clinical awake Muller’s Maneuver and/or drug-induced sleep endoscopy (DISE).