Everyone’s breathing is irregular at certain times during sleep. Your breathing may pause for a moment just as you fall asleep or as you awaken, and breathing during dreams tends to speed up and slow down in an irregular manner. These are all normal changes in breathing while asleep.
However, a person with sleep apnea frequently stops breathing entirely, and may hold his or her breath for a surprisingly long time. Each of these periods during which breathing has stopped is called an apnea episode or an apnea event of pauses in breathing. An apnea event may last from 10 seconds to more than a minute.
Sleep specialists measure sleep apnea in several ways. One is the Apnea Index, which is the number of apnea events during an hour of sleep. Another measure is how long the apnea episodes last. If a person has an Apnea Index of 20 (20 apnea episodes per hour of sleep) and if the apnea episodes last more than 10 seconds, a sleep specialist would diagnose the person as having moderately severe sleep apnea.
Another measure of sleep apnea is the amount of oxygen in the blood, called oxygen saturation. If you are not breathing, you are not taking in oxygen, so the oxygen in the blood stream is gradually used up and the organs in the body are not receiving the oxygen they need. The brain is very sensitive to being deprived of oxygen.
By morning, a person with sleep apnea may have experienced hundreds of fairly long episodes of pauses in breathing. Wouldn’t that person be aware of such a struggle to breathe? No. People with sleep apnea have been deprived of decent sleep for a long time. They usually are so desperately sleep deprived that they barely awaken to breathe and seldom are aware of doing so. Occasionally, apnea patients will notice awakening briefly with a snort, particularly during naps or when they nod off in a sitting position. They are likely to describe their problem as “insomnia.”
But most people with sleep apnea are the last to know it. Many have absolutely no complaints about their sleep. They will say they sleep “just fine,” and only wish their bedmate would stop bothering them about their snoring.
But listen! A bed partner who says you stop breathing during sleep is probably not making it up! A tape recording of a person’s sleeping sounds can be useful for convincing both that person and their doctor that he suffers from a breathing disorder (pauses in breathing) during sleep.