If a person starts taking long pauses in breathing while sleeping, and if this happens several times during the entire duration of sleep, then this disorder is called sleep apnea. A minimum break of 10 secs between two breaths amounts to a apneic event. These pauses in breathing happen when the airway in the throat is obstructed.
This sleep disorder has been prominently found in obese people. Other symptoms of sleep apnea include blood oxygen de-saturation of about 4% or more and variation in EEG frequency of 3 or more than 3%.
So, what causes sleep apnea? When we are awake, the throat muscles are stiff which allows easy passage of air to the lungs. However, during sleep these muscles are relaxed which normally do not block the airway unless the person has sleep apnea. This is also known as obstructive sleep apnea (OSA).
Most of the people suffering from sleep apnea are not aware of it, because they are not able to recollect that they had been struggling to breathe while in sleep. It is usually the other person sleeping in the bed who notices it first.
General sleep apnea symptoms include loud snoring, frequent silences in sleep, choking or gasping, abrupt awakening, morning headaches, insomnia, and excessive daytime sleepiness. Polysomnography, also known as 'Sleep Study' is a procedure used by doctors for diagnosing changes occurring during sleep.
Causes of Sleep Apnea
There are basically three types of sleep apnea. Obstructive sleep apnea is a condition caused when the throat muscles of the body relax and collapse during the sleep, as they are made up of collapsible soft tissue. Problems in the central nervous system can lead to a condition called Central sleep apnea.
In this condition, the instructions given by the brain (respiratory control center) to the throat might get muddled. This leads to a situation where the throat may not get the instruction to stay open, thus blocking the windpipe and causing sleep apnea.
Mixed sleep apnea is a condition wherein, the continuous and recurring obstructive apnea episode leads to central sleep apnea as well. Here are some other causes that lead to sleep apnea:
The extra fat in body and especially in the lungs makes it difficult for the air to pass through them, which might also lead to collapse of the airway passage. Also, sleep apnea aggravates obesity by making it difficult for the person suffering from it to lose weight. Thus, a person suffering from both obesity and sleep apnea is caught in a vicious circle.
Acid Reflux or GERD
The acid in the stomach enters the esophagus, damaging the esophageal tissue. If it gets more severe, it can damage vocal cord tissues. If one suffers from chronic acid reflux, then scars can develop inside the throat, blocking the airways, which can lead to sleep apnea. This disease arising due to acid reflux is called GERD/gastroesophageal reflux disease.
Asthma is a major deterrent of the airways as it causes convolution of the airways during sleep. This can easily cause the airways to collapse, thus leading to sleep apnea. Other allergies can also cause inflammation in the throat which might lead to sleep apnea.
Physical Shape of the Body
People born with relatively smaller windpipes are more vulnerable to sleep apnea than those born with bigger ones. The peculiar structure of a person's head and throat can cause sleep apnea. It can also be caused due to tonsils.
Smoking and consumption of alcohol causes throat muscles to relax thus making it difficult for the person to breathe during sleep. The possibility of GERD related heartburn which in itself is a cause for sleep apnea, also increases due to alcohol and tobacco chewing. Drug abuse and excessive usage of narcotics also lead to central sleep apnea.
Most people suffer from a combination of obstructive and central sleep apnea. The central sleep apnea might sometimes develop with long and severe OSA syndrome. Recently, complex sleep apnea has also been reported by researchers.
In this condition, patients show signs of OSA but when positive airway pressure is applied, they exhibit persistent central sleep apnea. Whatever the type may be, apnea treatment is essential. Healthy living is one of the ways to avoid sleep apnea as well as other ailments.