Sleep Evaluation

Sleep is a very personal time. We are unaware of our surroundings and are unprotected. We don’t know if we move, talk or snore. We are unable to present the best image of ourselves. We are vulnerable and helpless. Those we let into our personal lives, family, friends and loved ones, may tell us things about what we do during sleep, things we do not believe. Other times, we experience things that our loved ones do not see or have trouble believing. There may be no one to tell us if we are doing something unusual during our sleep.

We are reluctant to seek help for sleep problems. Sleep is a time when we are not consciously aware of our actions. We dislike having someone outside our inner circle involved in such a personal problem. In the past, it was not unusual for physicians to tell patients that a sleep problem was all in their heads. Now, the medical profession is more enlightened and knowledgeable. There are professionals who specialize in sleep problems.

This section is designed to help you answer questions you may have regarding the evaluation of sleep. Who should be evaluated? Who should do the evaluation? What kinds of tests are performed? Where should the tests be performed?

Absolute Indications for a Sleep Evaluation
Anyone who has symptoms or signs that suggest sleep apnea should discuss them with their physician. There are a few things that are absolute indicators of the need for a thorough evaluation – sleep testing. So how do you decide? When is your complaint an indicator of a serious medical condition?

Let’s start with the absolute indicators: those things that strongly suggest the presence of a significant breathing problem during sleep. The first is loud snoring. A sleep evaluation and testing are indicated if your snoring ‘rattles the rafters’, ‘shakes the walls’, can be heard at the other end of the house, is loud enough that it is easily heard outside the room or consistently drives your mate to another room to sleep.
If you are observed to have periods during your sleep when your breathing is seen to stop, sleep evaluation and testing are indicated. While normal individuals can have an occasional obstructive event associated with cession of breathing, repeated observations strongly indicate a problem.

If you are extremely sleepy, sleep evaluation and testing are indicated. Normal individuals sleep eight to nine hours a night and feel rested. It is abnormal to sleep ten to twelve hours and be sleepy during the waking hours. Sleeping more than ten hours a day means you should seek help. If you are sleeping seven to eight hours per night and falling asleep during normal activities, you should seek help. Falling asleep while doing dangerous activities such as driving or working with machinery is an absolute indication that sleep evaluation and testing are indicated.

When someone exhibits more than one of these three absolute indicators – loud snoring, observed cessation of breathing during sleep and excessive sleepiness – the question is not, “Does that person have apnea?” but, “How bad is it?” However, most people who suffer from significant obstructive sleep apnea, even many of those with severe apnea, do not report such extreme symptoms.

Symptoms of Obstructive Sleep Apnea
The symptoms of obstructive sleep apnea are primarily those of disturbed sleep, excessive sleepiness and non-refreshing sleep. Unfortunately, there is not one specific symptom to identify individuals with obstructive sleep apnea syndrome. Common symptoms are listed in Table One. If you are experiencing one or more of these symptoms, speak to your physician. A sleep evaluation and testing may be indicated.


“I can drink a cup of coffee at bedtime and go to sleep.”
“If I am not busy, I’ll nod off.”
“I’m fine as long as I’m active.”
“I can sleep 12 hours and still need a nap.”
“I can sleep anywhere, at any time.”
“When I snore, the roof shakes.”
“When I snore, they hear me at the other end of the house.”

Take the sleep quiz on this web site. It is another way of determining if you might have the syndrome. The Epworth scale can give you some insight as to the importance of your daytime symptoms. It can indicate sleep problems and suggest whether a sleep evaluation is needed. Both of these quizzes can help you decide if you should seek further advice and evaluation.

The only way to know if you have the syndrome is to be tested. A formal sleep test (polysomnogram) performed in a sleep center is the only way to be absolutely sure of what happens when you sleep. It is the test required by insurance companies to verify that a person has obstructive sleep apnea.

A sleep test (polysomnogram) measures sleep duration and stages, breathing, blood oxygen saturation, electrocardiogram, muscle contractions and body movements. It is a non-invasive test. All the sensors are strapped on or attached with adhesive material. A polysomnogram is a highly complex series of measurements. It is the only test that can answer the question: “Do I have sleep apnea?”

Many things are measured during a polysomnogram. The tests included are an electroencephalogram (EEG), electromyograms of chins and legs (EMG), electro-oculogram (EOG), electrocardiogram (ECG), airflow through the nose and mouth, chest and abdominal movements, limb movements, blood oxygen saturation and body position. For the electroencephalogram (EEG), a measurement of brain waves, eight to ten electrodes are glued to the head and scalp. The EEG, EMG and EOG demonstrate a characteristic pattern during sleep allowing a determination of the depth of sleep. The electromyogram is a measurement of muscle tone. The electro-oculogram records the movement of the eyes. These three tests, the EEG, the EOG, and the chin EMG are used to define sleep.

Breathing measurements are made from airflow, chest and abdominal wall movements, and the blood oxygen level sensor recordings. Air movement through the nose and mouth is measured with a sensor worn under the nose, much like the tubing used to give oxygen to a sick person. The chest and abdominal wall movements are recorded from elastic belts worn around the chest and abdomen.

The remaining recordings measure changes that may result from apnea or may occur independently of apnea. Body movements during sleep occur very commonly. They may be a problem for the person who has them, they may just be an observation without significant effects to the person, or they may be the result of sleep apnea. The visual monitoring of the person while sleep adds information regarding the nature of the movements that occur.

A recording from a polysomnogram during a normal period of sleep is shown in Figure 1.


Each type of measurement performed on a polysomnogram requires special knowledge of the test. Often, a specially trained technician carries out each type of test. However, a polysomnogram technician (sleep technician) must be skilled in multiple physiologic testing tasks. It is very important that properly trained technicians perform the test.

Polysomnograms are performed in specialized testing centers. The American Academy of Sleep Medicine, the organization of physicians and interested medical professionals, has set standards for sleep testing centers. The standards define the training requirements for the personnel, the procedure for the testing techniques, the physical requirements of the facility and appropriate working hours and responsibilities for the staff. In short, the Academy defines what is required to perform the testing in an appropriate manner. The Academy has a program to accredit sleep centers and sets very high standards. The best way to be sure that you have a sleep study of good quality is to be tested at a sleep center accredited by the American Academy of Sleep Medicine.

Are there alternatives to the polysomnography test for sleep apnea? The American Academy of Sleep Medicine, Medicare and essentially all health insurance companies require a polysomnogram performed in a sleep center for the diagnosis of Sleep Apnea Syndrome. Several testing techniques are used to screen for the problem. If an abnormal result is obtained, a polysomnogram is usually required.
The most commonly used screening test is an overnight oximetry.

Oximetry Testing
Oximetry testing is a widely available technique. It is used to determine the oxygen level in a person’s blood. A small sensor with a red light is attached to the finger and the oxygen saturation is determined. It is the same sensor used during the polysomnogram. The oximetry-testing unit has a memory and records the blood oxygen level during sleep. Changes in the oxygen level can suggest, but not diagnose, sleep apnea.

Home Sleep Testing
There are a number of commercially available home testing systems. Below is an example of home testing equipment:

People frequently ask how to select a sleep physician or a sleep center that can provide advice and help. As always, the informed person is the wise consumer. Ask your physician. Ask friends and colleagues. Check out reference sources.

Sleep physicians in each state are listed on the American Board of Sleep Medicine’s web site. Most states have web sites that list local sleep physicians and their qualifications.

Sleep testing can be found in many locations owned by physicians, hospitals and business companies. How do you find a center that has demonstrated a high quality track record? Centers accredited by the American Academy of Sleep Medicine meet the requirement. They are listed at the Academy’s web site.

If you have been recommended to a center, check to see if it is accredited by the Academy. Also, determine the ownership. Centers owned and operated by physicians or hospitals are usually a good choice. Centers owned and operated by medical equipment companies and business entrepreneurs should be suspect. What should be of concern to the potential patient? Who is the physician responsible for the testing and the interpretation of the test? Is he a local specialist? Can he be seen if you need help with your sleep problem? See ‘How to Choose a Sleep Center’ on the resources page for more information.

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