The Greek word "apnea" literally
means "without breath". Sleep apnea is an
illness whereby people suffer from pauses in breathing
many times during each night's sleep. Those suffering
from it often complain about of excessive daytime
sleepiness or bad sleep. It can occur to anyone at
any age, and is a serious and life-threatening disorder
which affects more men than women, and those with
narcolepsy (see Narcolepsy)
also are more prone to getting sleep apnea. Once developed,
the illness seems to remain for life, where in some
cases the symptoms reach maximum severity very quickly
while in other cases the symptoms commences gradually
and require years before reaching its most serious
level.
There are three types of sleep apnea,
central sleep apnea, upper airway or obstructive sleep
apnea and mixed sleep apnea. Central sleep apnea is
a rare central nervous system disorder. People suffering
from this type of sleep apnea when asleep, the diaphragm
stops moving because the sleeping brain fails to send
impulses through the nerves which control the movement
of the diaphragm. When the diaphragm stops functioning,
breathing stops as well. Upper airway or obstructive
sleep apnea is a more common and serious type of apnea.
This type of apnea does not affect the diaphragm,
but there is an abnormal loss of tone in the muscles
of the tongue, throat, larynx during sleep. The result
is that at the onset of or during sleep, the throat
collapses and blocks the airway. During a apneic episode,
the diaphragm continues to contract rhythmically with
a progressively greater effort against the closed
airway until a partial or complete awakening occurs
and normal breathing is resumed. Mixed sleep apnea
is a combination of the above two types. This is more
common in people who also have narcolepsy. These apneic
episodes always begin with central sleep apnea, then
turning into upper airway sleep apnea. However, the
reverse order is not seen.