Snoring can ... be a symptom of sleep apnea, which can be life-threatening. While snoring is caused by narrow airways, sleep apnea is a true breathing obstruction, which requires the sleeper to awaken to begin breathing again. A person with sleep apnea wakes up many times a night to regain breathing, but usually remembers nothing at all about the awakenings. The sleep partner of a person with sleep apnea usually remembers the awakenings and is generally a good witness of the incidents.