Quite frequently, a patient will tell me they’ve become aware that they snore, or that their partner has noticed it. Their solution is I order a sleep study to evaluate the snoring and test for sleep apnea. In fact, I also see this "sleep study evaluation" prescription quite often ordered by primary care physicians in my local area. Inevitably the study will come back abnormal and the doctor will prescribe a CPAP machine for sleep apnea. However, the patient often isn’t compliant and doesn’t use the machine regularly (or at all). Thus the snoring problem (and underlying condition) is never solved.
But what’s lacking here is a basic understanding of the difference between snoring and obstructive sleep apnea. Only sleep apnea is looked at in the study, whereas regular snoring isn’t.** What’s the Difference?**
Snoring is caused by sound echoing in the soft palate, which is the back roof of your mouth. Snoring can be triggered by nasal obstruction, sleep position, and narrowing of the pharynx - which can also cause sleep apnea. Treating these triggers may include surgically opening the pharynx or cutting some of the palate tissue with a laser. But while these cure the snoring, they will not help sleep apnea, which happens further down the throat. So a diagnosis of nasal obstruction or poor sleep position will indicate snoring, and may easily be treated. But a diagnosis of a narrowing pharynx may be sleep apnea, and should be tested further.
How Sleep Apnea Occurs
Solid cartilage keeps the airways of the nose and windpipe open. The pharynx, which is located between them, has to stay flexible since it helps us swallow food and make sounds. The dilator pharyngeal muscles of the throat act as a bridge to hold open the airways of the pharynx. These help protect it from collapsing from fat tissue in the neck or pressure generated from air pulling into the lungs.
When we’re awake, it’s easy for the muscles to maintain shape and keep the passage open. At night, all the muscles, including the dilator pharyngeal, become relaxed, and can easily lead to collapse. In addition, individual health conditions such as obesity may already restrict airways in the back of the throat. The diaphragm, a respiratory muscle on the bottom of the lungs, is typically supposed to help generate the pressure to keep the airways open. But when a person is obese, too much negative pressure is created, the diaphragm gives up and airflow stays restricted.
Learn how sleep apnea is diagnosed and treated in part two: Evaluating Sleep Apnea
Eli Hendel, M.D., is a board-certified internist/pulmonary specialist with board certification in Sleep Medicine. An Assistant Clinical Professor of Medicine at Keck-University of Southern California School of Medicine, and Qualified Medical Examiner for the State of California Department of Industrial Relations, his areas include asthma, COPD, sleep disorders, obstructive sleep apnea, and occupational lung diseases. Favorite hobby? Playing jazz music. Find him on Twitter @Lung_doctor.