Continuing our video series, Dr. Jerome Hester explains “How sleep apnea works”.
The following is transcript of the video for your convenience:
It is normal for humans as they go through the night to dive into periods of deep sleep. During these periods of deep sleep it is normal for the body to go into complete muscle relaxation. The area from approximately behind the nasal cavity to behind the back of the tongue is a muscular tube and as we go into deep sleep these areas can relax.
In those individuals who have either too narrow of an airway or too floppy, for lack of a better term, of an airway, these areas can close down to the point where breathing is interrupted. This can be a complete interruption, or an apnea, where the breathing stops completely, or a partial obstruction which is known as a hypopnea. Interestingly a hypopnea may not be obvious to an individual watching someone sleep and so therefore just observation of someone sleeping is not an accurate way of measuring sleep apnea.
Both of these issues, however, cause disruption of sleep. The body has a safety mechanism in place where the brain will pull us out of deep sleep into a more superficial layer of sleep, enabling muscle tone to return to the airway and the patient is able to breathe again. However, this leads to disruption of deep sleep over and over again through the nighttime. In the worst cases this can lead to actual fatigue during the day because of the lack of deep, uninterrupted sleep. However, fatigue is a somewhat subjective evaluation by the patient and many times the individual will deny fatigue or put it onto some other reason such as pressure at work or issues at home. Other things can happen that are manifestations of this problem such as lack of attention span concentration difficulties. We especially see these in the younger patients, the children and the adolescents where fatigue actually is absent commonly but problems with cognitive functioning are much more common.
At the same time, issues are going on with the drop in oxygen level when the breathing is interrupted. This can cause long term problems with the brain itself, once again leading to issues with cognitive functioning. But also with the heart and other tissues in the body with repetitive lower oxygen levels happening throughout the night. At the time of obstruction a large release of adrenaline also occurs, which can cause increased pressure on the heart itself and lead to problems such as differences in heart blood pressure which can cause long term problems for the patient.