Insomnia Test: How Bad Is Your Sleep, Really?

The Insomnia Severity Index

Think about the last two weeks. For the first three questions, rate how severe each problem has been; for the rest, pick the answer closest to how you feel.

Insomnia Severity Index © Charles M. Morin, 1993. Bastien, Vallières & Morin, Sleep Medicine, 2001.

Reading your score

• 0–7: no clinically significant insomnia. Your sleep may still be imperfect, but it is not in the range that usually needs treatment.
• 8–14: subthreshold insomnia. A real pattern that is not yet doing much damage — and the easiest stage at which to turn it around.
• 15–21: clinical insomnia, moderate. This is the range most of our patients arrive in, and the range where CBT-I has its strongest evidence.
• 22–28: clinical insomnia, severe. Sleep is dominating your days as well as your nights; treatment is worth starting soon.

Whatever your band, remember what the number is: a measure of severity, not a diagnosis. (If you want the longer version of what insomnia is and why it sticks, our insomnia explainer covers the definition, the types and the three-P model.) Two people with a score of 18 can need very different care — one may have textbook chronic insomnia, the other an untreated breathing problem, a shifted body clock or a medication side effect. That sorting is a clinician's job, and it is the first thing we do at an initial appointment.

Why we keep re-scoring it

At Michigan Sleep Center the ISI is a working tool, not a formality. Your first score goes in your chart next to two weeks of sleep diary; together they set the sleep window your clinician builds your CBT-I plan around. Halfway through treatment the questionnaire comes out again, and once more at the end, so both of you can see the change in the same units it was measured in at the start rather than relying on memory of how bad things were. Michigan patients who arrive in the low twenties commonly finish in single digits — and because they were tracked, they know it.

If your score points toward treatment, the next page to read is insomnia treatment in Michigan, which explains what a course of CBT-I involves here. If a lot of your sleeplessness is a racing mind, anxiety therapy may be part of the answer. And if the person next to you reports snoring or gasping, read Do you need a sleep study? before anything else.

Is this the same insomnia test a sleep clinic would give me?

Yes — the seven questions above are the Insomnia Severity Index, the questionnaire used in sleep clinics and insomnia research worldwide, including at Michigan Sleep Center. What a clinic adds is the interpretation: your clinician reads the number alongside your sleep history, your schedule and anything else going on, which is why the score on its own is a starting point rather than a verdict.

Could a high score mean sleep apnea rather than insomnia?

It could contribute to one. The ISI measures how disrupted and distressing your sleep is, not why. Loud snoring, gasping awake or pauses in breathing that someone else has noticed point toward a breathing problem, and sleep apnea and insomnia often occur together — we treat the insomnia, we have partners who treat the apnea, and our clinician coordinates any referral that is needed.

How often should I retake the test?

Every few weeks is enough to see a trend; night-to-night noise makes daily scoring misleading. In treatment, our clinicians typically re-score the ISI at the midpoint and the end of a CBT-I course so that progress is measured the same way it was at the start. A drop of six points or more is generally treated as a meaningful improvement.

My score was low but I still sleep badly. Am I fine?

Not necessarily. A low score usually means your sleep problem is recent, mild or not yet costing you much during the day. If you have doubts, keep a simple sleep diary for two weeks and repeat the questionnaire; and if the nights are getting worse, being seen early is easier than waiting for a higher number.