What is Obstructive Sleep Apnea (OSA)?
To understand OSA, it is first important to understand the actual process of sleep. During sleep, the body alternates between non-rapid eye movement (NREM) and rapid eye movement (REM) phases. In NREM, the parasympathetic nervous system (PSNS) predominates, which causes lower blood pressure, a slowed heart rate, and muscle relaxation. Before waking, the REM phase occurs, which is predominated by the sympathetic nervous system (SNS). The SNS causes higher blood pressure, a higher heart rate, and muscle contractions.
Obstructive sleep apnea can be referred to as a disorder in which one or more pauses in breathing or shallow breaths during sleep occur. Pauses in breathing may differ in duration, from a few seconds to a minute, or in frequency, from 5 to 30 times during one hour. After each pause, breathing resumes as normal. These pauses in breathing happen because of a blockage of the airway during sleep. This blockage causes the chest muscles and the diaphragm to work harder in order to open the airways. As a result, loud snoring occurs as the body tries harder and harder to open the airway.
Though OSA may mainly display itself through loud snoring during sleep, it also is characterize by poor oxygen intake, which can cause a variety of symptoms as the body does not receive the oxygen that it needs.