Insomnia
Patient Education

Patient Guide

Common Tests or Labs to Diagnose Insomnia

Most cases of insomnia can be recognized and treated by taking a thorough history and comprehensive physical examination. However there are three diagnostic tests that are available:

Test	What is it?	What Happens?	What is Measured?
Polysomnography	Performed when insomnia does not dissipate with therapy; pinpoints other causes	Small electrodes (metal discs) are placed on the body and head with an adhesive. These measure brain activity, heart and breathing rates and rhythm, body muscle movements, and eye movement. The test takes 6 hours overnight in a sleep lab.	females = 2.4-6.0 mg/dL males = 3.4-7.0 mg/dL
Actigraphy	Measures sleep-wake cycles	A small, watch-sized device is worn for weeks or months to assess sleep-wake cycles.	Normal is detecting a typical sleep-wake pattern. Also used to assess the benefit of drug and behavioral intervention for sleep patterns.
Multiple Sleep Latency Test (MSLT)	Synonymous with nap study; rarely used for regular insomnia	You are placed on a bed and left for 20 minutes to fall asleep. The technician monitors for sleep onset and REM patterns. After 20 minutes, you are awakened. This is repeated in several 2 hour intervals over a 10 hour period.	If REM occurs too early, it may suggest narcolepsy (excessive sleepiness).

Test

What is it?

What Happens?

What is Measured?

Polysomnography

Performed when insomnia does not dissipate with therapy; pinpoints other causes

Small electrodes (metal discs) are placed on the body and head with an adhesive. These measure brain activity, heart and breathing rates and rhythm, body muscle movements, and eye movement. The test takes 6 hours overnight in a sleep lab.

females = 2.4-6.0 mg/dL

males = 3.4-7.0 mg/dL

Actigraphy

Measures sleep-wake cycles

A small, watch-sized device is worn for weeks or months to assess sleep-wake cycles.

Normal is detecting a typical sleep-wake pattern.

Also used to assess the benefit of drug and behavioral intervention for sleep patterns.

Multiple Sleep Latency Test (MSLT)

Synonymous with nap study; rarely used for regular insomnia

You are placed on a bed and left for 20 minutes to fall asleep. The technician monitors for sleep onset and REM patterns. After 20 minutes, you are awakened. This is repeated in several 2 hour intervals over a 10 hour period.

If REM occurs too early, it may suggest narcolepsy (excessive sleepiness).

Written by Barbara Hales, M.D.

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