Sleep Apnea is a common but serious sleep disorder. The disorder is caused by repetitive periods when airflow is interrupted during sleep due to a narrowing or closure to the throat. A complete blockage of airflow is an apnea, and a partial interruption is a hypopnea. Each apnea or hypopnea can result in drops in oxygen levels and brief awakenings or sleep disturbances. Typical symptoms of Sleep Apnea are snoring, snorting or gasping during sleep, unrefreshed sleep, and daytime sleepiness.