What is sleep apnea?

To better understand sleep apnea, we first need to understand the definition of word. Apnea is a Greek word that means "without breath". The condition of apnea is where someone has drastically slowed their breaths or even stopped breathing. So when we put apnea together with the word sleep, this literally means stopping breathing during sleep.

The problem with these apneic periods is that since the person is not taking in any fresh air, the oxygen levels in their blood falls, to sometimes dangerous levels. Long periods of these low oxygen levels is called Hypoxia. Persistent hypoxia is evidenced by symptoms that occur during the waking hours. If the condition progresses enough, other, more serious conditions may develop.

There are three types of sleep apnea: obstructive, central, and mixed; of the three, obstructive sleep apnea (OSA) is the most common. No matter which one is the cause, in all three, people with untreated sleep apnea either stop breathing repeatedly during their sleep, sometimes hundreds of times during the night and often for a minute or longer, or breathe too shallow for adequate respiration.

When a sufferer of OSA sleeps, the muscles at the base of the throat relax, and cause a blockage or obstruction in the throat. Sometimes the blockage is caused by greatly enlarged tonsils or adenoids. This results in labored breathing. When the airway gets to the point that it is completely blocked, breathing stops. Classic symptoms are defined as snoring, that grows louder and louder, followed by a silent period of time in which no breathing is taking place. This is the apnea period. During this time, the person can look like they are gasping or struggling to breathe. The brain detects the low level of oxygen in the blood (hypoxia) and in order to prevent suffocation, the brain triggers a release of a chemical messenger, adrenaline. This chemical shocks the consciousness centers of the brain and causes a partial awakening. This is the classic loud snort or gasp. The awakening causes the muscles to open the airway, the heart rate races in response to the adrenaline and causes a spike in blood pressure. Several breaths are then taken, blowing off the carbon dioxide and restoring oxygen to the blood. The blood chemistry returns to near normal. Then the cycle repeats. As many as 500 times night.

In central sleep apnea, the airway is not blocked, like it is in OSA, but the brain fails to signal the muscles to breathe. Central sleep apnea is thought to be related to an inappropriate breathing response to levels of oxygen and carbon dioxide in the blood stream. It can be a life threatening condition. It is rare in children.

Mixed sleep apnea, as the name implies, is a combination of the two. With each apnea event, the brain briefly arouses sleep apnea victims from sleep in order for them to resume breathing, but consequently sleep is extremely fragmented and of poor quality. This is why one of the main symptoms of sleep apnea is daytime drowsiness.

Sleep apnea is very common, as common as adult diabetes. Over 12 million Americans have this condition. If left untreated, it can cause serious health problems, including death.