When the upper airway is blocked causing significant airflow disruption, chronic snoring can occur, which is a symptom of Obstructive Sleep Apnea . This can cause reduced airflow into the lungs lowers blood-oxygen levels.
A person with sleep apnea may wake 50 or more times per hour without having any memory of it. These are called micro-arousals and last just long enough to restore muscle tone to the airway so you can breathe. Unfortunately, all those micro-arousals prevent a restful sleep.