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What is sleep apnea?



Sleep Apnea is a condition where there are brief periods during sleep in which your airway relaxes and you do not get enough air to your lungs. Often disregarded as troublesome or something you just inherited from a relative, it is actually a serious, potentially life-threatening condition that is far more common than generally understood. Sleep apnea was first described in 1965, but did not gain attention until the late 1980’s. There are three types of sleep apnea, obstructive, central, and mixed.


Obstructive Sleep Apnea (OSA) is the most common form of sleep apnea. It is caused by a collapse of soft tissue in the rear of the throat creating a temporary blockage in the airway. Because of this, the sleeper can stop breathing for anywhere from 10 seconds to 3 minutes, with events recurring up to 100 times an hour in the most severe cases.


Central Sleep Apnea occurs when the brain fails to signal the diaphragm and chest muscles to breathe. Central sleep apnea can occur in newborns, particularly those born prematurely. It is also seen in older adults or those suffering from heart disease or neurological disorders. 

Mixed Sleep Apnea
 is characterized by a combination of both apneas listed above. This disorder initially occurs as central sleep apnea (where the brain fails to signal the chest to breathe); then when the diaphragm suddenly begins moving, the airway is blocked by an obstruction (obstructive sleep apnea). It is not uncommon for someone to experience all three types of apnea in a single night's sleep.


What are the symptoms of sleep apnea?

Often, the patient is not the one who complains to the physician about sleep apnea, but rather the bed partner. Sleep apnea is most often associated with loud snoring and evident pauses in breathing; it can annoy and/or frighten the sleeping partnter. Symptoms the patient may notice include:

  • Excessive daytime sleepiness (falling asleep easily & sometimes inappropriately)
  • Morning headaches
  • History of high blood pressure
  • Memory problems or poor judgment
  • Feelings of depression
  • Gastro-esophageal reflux (heartburn)
  • Impotence
  • Nocturia (frequent night time urination)
  • Difficulty concentrating
  • Personality changes or irritability

What makes sleep apnea dangerous?

When breathing stops, the oxygen level in the blood falls which can put a strain on the heart and lungs. Fortunately, when the brain notices this drop, it sends a signal to the body that there is trouble and a strong signal to resume breathing occurs. This action causes a brief, but often unnoticeable, arousal from sleep.


As a result of these disruptions, the body is not able to go into the deeper stages of sleep which include REM sleep (the deep, restorative sleep cycle where dreaming occurs) and Delta sleep, which is also important for your overall well-being. The result is that the sufferer will wake up the next day still feeling tired, and may experience morning headaches because of the decreased oxygen.


Are there other consequences?

As most people know, sleep is important for your overall health. If it wasn't, why would we need to spend one-third of our lives doing it? The most immediate effect of sleep apnea is daytime fatigue and the risk of falling asleep at work or while driving. Other potential effects of sleep apnea include serious health problems such as high blood pressure, heart problems, diabetes and stroke. It can also lead to depression, irritability, sexual dysfunction, and learning and memory difficulties. It has been estimated that up to 50 percent of sleep apnea sufferers have high blood pressure. There is a definite link between sleep apnea and diabetes, though it is not clear that one causes the other it is just that many people have both. Patients in Europe who have diabetes are automatically screened for sleep apnea; those with sleep apnea are screened for diabetes. Treating sleep apnea has been shown to improve glucose control in diabetics.


What are the risk factors for sleep apnea?

  • Family history
  • Excess weight
  • Large neck size
  • Recessed chin
  • Abnormalities in the structure of the upper airway
  • Smoking
  • Alcohol use
  • Advancing age  

How is sleep apnea diagnosed?


In the past, sleep apnea could only be diagnosed by taking an overnight sleep study, called a polysomnography or PSG, in a specialized sleep testing facility. A PSG records multiple biophysiological signals throughout the night after sensors have been applied over much of the body. In addition to being able to tell if you have sleep apnea, a PSG can tell what percentage of time you are spending in each stage of sleep (which is a measurement of how efficiently you are sleeping) and whether or not you have other, more rare disorders such as a sleep movement disorder or narcolepsy.


Your physician can also determine if you have sleep apnea by asking you a series of questions or by having you fill out a questionnaire. Then, based on this presumed diagnosis, he can order a Home Sleep Test (HST). The advantage of the HST is that you are being recorded in your own bed; it is more likely to reflect what actually happens each night. It is also significantly less expensive and more convenient.


NEXT: The Benefits of Home Sleep Testing   

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