How Sleep Labs Work

Shift workers are notoriously prone to experiencing sleeping problems due to split sleep schedules and other sleeping irregularities.
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It's normal to occasionally build up a bit of sleep debt or fight your circadian cycle. Perhaps your child falls ill and requires temporary round-the-clock care. Or maybe your job requires you cover the occasional night shift. But what's not natural -- or healthy -- is continually maxing out your sleep credit line or chronically altering your body's sleep schedule. The human body must have solid rest on a regular and regulated basis, or problems of all sorts will ensue. For people with sleep disorders, not getting proper sleep is a common, if obvious, issue.

Sleep disorders can have huge ramifications on a person's day-to-day life, as well as affect his or her long-term health outlook. Sleep deprivation and other problematic symptoms often result, further fueling the negative effects. Take obstructive sleep apnea, for example. People who develop this sleep disorder will repeatedly, and often unknowingly, wake themselves throughout the night when the muscles in their throats relax and structures in their mouths and throats move to block their airways. When an apnea sufferer's brain realizes that no air is coming its way, it will jolt the sleeper awake to tighten the muscles and clear the breathing passage. This can happen over and over on a nightly basis, meaning people with sleep apnea never achieve meaningful rest cycles.


Those who experience this disorder are often unaware how restless they are while sleeping, but that lack of adequate downtime causes them to be overly tired during the day. Ongoing daytime drowsiness is bad enough, what with its tendency to cause people to be irritable, irrational and unfocused, but sleep apnea also contributes to much more serious consequences as well, including hypertension which can lead to an increased risk of stroke and heart failure.

Luckily, obstructive sleep apnea is usually easily diagnosed and treated with a visit to a sleep lab, as are many other sleep disorders. On the following pages, we'll take a closer look at sleep labs, and what they do.


Sleep Lab Landscapes

For people who feel they're overly tired or are experiencing other sleep-related troubles, the first line of defense is typically their primary care physician, who will perform a preliminary evaluation and physical.

Before their appointments, patients are advised to keep a sleep diary for a couple of weeks. The information they collect should include what time they went to bed and got up in the morning -- as well as whether or not they felt rested during the day or in serious need of a nap. They'll also want to record their quality of sleep. Did it take long to fall asleep? Did they wake? How many times? For how long? Coming armed with this sort of knowledge will help the doctor determine an underlying cause.


If the PCP can't diagnose the issue, or suspects the cause but needs confirmation, he or she may refer that patient to a sleep lab to see a specialist. Sleep labs are increasingly common as the importance of treating sleep disorders becomes more evident. Some 70 million Americans experience a sleep disorder, and with more than 80 different types of disorders out there, symptoms can vary quite a bit [source: American Academy of Sleep Medicine]. Many of the disorders are mild annoyances, while others are severe disturbances so serious they can be fatal. Some are quite common -- such as general insomnia, which affects about 30 percent of adults at any given time and about 10 percent of adults chronically [source: American Academy of Sleep Medicine]. Others are incredibly rare -- such as fatal familial insomnia, which affects the members of only about 40 families in the world [source: 20/20]. Other problems considered sleep disorders include restless leg syndrome, habitual snoring, sleep starts, sleep paralysis, confusion arousals, teeth grinding and circadian rhythm sleep disorders.

At sleep labs, patients are interviewed by a specialist, and following that, they may be asked to undergo a polysomnogram, or sleep study. During the test, technicians and technologists monitor patients' sleep in a variety of ways, to help diagnose disorders. Polysomnograms often take the form of overnight sleep studies, but can also occur during the day, to diagnose conditions such as narcolepsy. People who are diagnosed with sleep disorders that require treatment devices, such as obstructive sleep apnea, may return to have the devices calibrated. And some sleep labs are also involved in sleep research, recruiting volunteers to assist in scientific studies.

Next up, we'll delve into what goes on during an overnight polysomnogram.


Sleep Lab Studies

The preparations for polysomnographic recording sessions typically proceed like this.
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Let's look at the steps of a polysomnogram in the form of an overnight sleep study. The patient arrives in the evening, armed with items such as pajamas, toothbrush, book, pillow and morning attire. The sleep lab workers escort him to a private room where he can put his PJs on and get settled in for the night.

Next, a lab technician will hook up an assortment of electrodes to the patient's skin and scalp, along with two belts to encircle his chest and waist. These are to measure how much effort he exerts to breathe while sleeping, and another attachment called an oximeter measures how much oxygen is in his blood.


The electrodes, however, are the most important components -- they record all sorts of activity throughout the evening. Different ones are dedicated to conducting different tests: The electroencephalogram (EEG) measures brainwaves, the electromyogram (EMG) measures muscle activity, the electrooculogram (EOG) measures eye movements, and the electrocardiogram (EKG) measures heart activity. The sleep lab technologists will also hook up a sensor to measure airflow through the nose and mouth, and set up a microphone to record snores and a video camera to get a visual record of body movement.

Patients are allowed to spend some time relaxing, perhaps reading or watching TV, and then they're supposed to fall asleep when ready. It might seem odd, but according to sleep labs, most patients don't have much trouble going to sleep -- or at least, much trouble in regard to the electrodes and other strange apparatus involved in the process. Then throughout the evening, all the results will pour in to the monitoring station. Once the results are in, a sleep lab specialist will interpret the results to try to determine a diagnosis and decide on an appropriate form of treatment.

On the next page, we'll look at some of the common treatments someone might receive from a sleep lab.


Sleep Lab Results

Not all sleep disorders require direct treatment or a full polysomnogram like the one described on the previous page. And not all the conditions that are considered sleep disorders are distressing or overly damaging to the person experiencing them. Still, even people with more minor disorders can still be assessed and potentially alleviated by sleep lab staff if they seek treatment. Take exploding head syndrome -- something much less dramatic than it sounds. The disorder is characterized by loud imagined noises that startle sleepers awake. For many people, this sort of thing is simply an occasional annoyance to be borne, and only people who experience it to a debilitating extent need to be worried about talking to a specialist.

Many sleep disorders are common in childhood but disappear in adulthood, like sleepwalking and sleep terrors, so if grownups are still experiencing them, that might be cause to visit a sleep doctor. Especially since for many adults who do still experience conditions traditionally linked to children, it can be the sign of another underlying sleep disorder or the result of a certain medications, mental health disorders, medical conditions or substance abuse. In fact, these other factors frequently trigger additional sleep disorders.


The treatments for sleep disorders vary wildly. A standard one for obstructive sleep apnea is continuous positive airway pressure, commonly referred to as CPAP. At bedtime, people who need to use a CPAP system put on a mask and turn on a small wall unit that contains a fan, and sometimes a humidifier as well. Once the mask is snuggly in place, the air flowing from the fan keeps the person's airway open.

Sleep lab workers help patients fine-tune how fast the air flows, since different pressure settings work better for different people. In order to find the ideal air flow and humidity levels, sleep labs perform a titration procedure, during which they analyze how well the CPAP is performing. Newer CPAP units can even monitor a patient's usage, and sleep lab technologists can use this information to further calibrate the machine's programming.

Other treatments commonly recommended for sleep disorders by sleep labs are bright light therapy and melatonin supplements to treat issues with a person's internal circadian rhythm. Medications may also be prescribed for sleep disorders, and sometimes cognitive behavioral therapy strategies are used to help people develop healthier sleeping habits. These can include learning how to better control outside stimuli, setting up strict patterns and restrictions concerning sleeping schedules, becoming proficient at relaxation techniques and understanding biofeedback cues. Psychotherapy sessions may be another asset in a management plan.

Sleep specialists can also educate those who have trouble sleeping on how to practice smarter sleep hygiene. This includes common sense steps such as avoiding eating, smoking, drinking and exercising close to bedtime, as well as setting up a proper sleeping environment. A lot can go into getting a good night's rest, and sleep labs are available to make sure people know it. More info on the next page.


Lots More Information

Related Articles

  • American Academy of Sleep Medicine Sleep Education Web site. (Aug. 5, 2011)
  • American Academy of Sleep Medicine Web site. (Aug. 5, 2011)
  • "Fatal Familial Insomnia." 20/20. (Aug. 5, 2011)
  • National Sleep Foundation Web site. (Aug. 5, 2011)
  • "Sleep Disorders." Mayo Clinic. (Aug. 5, 2011)
  • "Sleep Disorders Center." WebMD. (Aug. 5, 2011)
  • Sleep for Science Web site. (Aug. 5, 2011)
  • Web site. (Aug. 5, 2011)
  • Turner, Rebecca. "Fatal Familial Insomnia: The FFI Sleep Disorder." World of Lucid Dreaming. (Aug. 5, 2011)
  • Webster, Molly. "Can You Catch Up on Lost Sleep?
  • Wollenberg, Anne. "Time to wake up to sleep disorders." Guardian. July 28, 2008. (Aug. 5, 2011)