Testing for Insomnia

Polysomnography and Actigraphy Can Distinguish Other Conditions

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If, after careful discussion with your doctor, you are still uncertain if you have insomnia or another sleep disorder, it may be necessary to pursue other testing. In most cases, it is not necessary to conduct further tests for insomnia because the diagnosis is not in doubt. However, an astute physician may suspect sleep apnea, restless legs syndrome, or a circadian rhythm disorder. In these cases, additional testing may be useful.

To discover the answers to these questions, let’s review an excerpt from UpToDate -- a trusted electronic medical reference used by health care providers and patients alike. Then, read on to learn additional information about what all of this means for you.

"Laboratory tests may be recommended to help identify underlying medical or sleep disorders, although this is not required for everyone with insomnia. Laboratory tests may include polysomnography or actigraphy:
  • Polysomnography — Polysomnography is a formal sleep study done in a sleep laboratory. It uses monitors that are attached to your body to record movement, brain activity, breathing, and other physiologic functions. This test may be used when an underlying sleep disorder is suspected or if your insomnia has not responded to treatment.
  • Actigraphy — Actigraphy records activity and movement with a monitor or motion detector, generally worn on the wrist. The test is conducted over several days and nights at home to gather information about how much and at what time you are actually sleeping."

As suggested above, these tests are best used to rule out other causes of difficulty falling or staying asleep, or sleep that is not restorative, the characteristic symptoms of insomnia. A thorough history, especially with the input of a bed partner, may clarify these points without the need of further testing.

However, polysomnography and actigraphy may add certainty if the diagnosis is in doubt.

Polysomnography is the gold standard to diagnose sleep disorders. It is a way to carefully monitor various elements of your sleep. The test typically occurs in a sleep center. There are a number of monitors used to record movements, breathing patterns, the electrical patterns of your brain (called an EEG), and other things like your heart rhythm and blood oxygen level. The polysomnogram may identify a distinct cause to your difficulty sleeping.

If your sleep is disrupted because your legs move around at night (such as occurs in restless legs syndrome), then the treatment will differ. If you have disrupted breathing (which is common in sleep apnea), then this likewise will have a unique treatment. Rarely, other conditions, such as nocturnal seizures, may be identified.

In addition, actigraphy may be a useful test to diagnose other sleep disorders. It is most commonly used with a sleep diary to identify circadian rhythm sleep disorders.

These conditions are characterized by a disrupted timing to sleep. The actigraph can record movement and produces a record over weeks (or longer) that will reveal your sleep pattern. This may uncover conditions such as delayed or advanced sleep phase syndrome.

For most people suffering from insomnia, further testing is not necessary to recognize the problem. However, if you have other symptoms that raise suspicion or your condition is not responding to standard treatments, these additional tests may provide the answers that you need.

Want to learn more? See UpToDate's topic, "Insomnia," for additional in-depth medical information.


Bonnet, Michael et al. "Insomnia." UpToDate. Accessed: January 2012.

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