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Insomnia Symptoms & Diagnosis

Wondering whether what you have is insomnia? Here's what the condition actually is, how it's diagnosed, and what else can cause the same broken nights.

Written by George Wang
Medically reviewed by Robert Stevens, MD
Reviewed
11articles
5 minper article
Oct 2026last reviewed article

What to know first

  • Chronic insomnia disorder involves difficulty falling asleep, staying asleep or waking too early, along with a daytime impairment. These symptoms need to occur at least three nights a week for at least three months, despite adequate opportunity for sleep, and cannot be explained solely by another disorder or substance use.
  • No quantitative sleep parameter defines insomnia disorder. What the AASM's 2008 guideline describes as common complaints are an average sleep latency over 30 minutes, time awake after falling asleep over 30 minutes, sleep efficiency under 85%, or total sleep time under six and a half hours.
  • There is no hours threshold anywhere in the criteria. Insomnia is defined by difficulty and daytime impact, not by total sleep time.
  • Around 30–36% of adults report at least one insomnia symptom; roughly 6–10% meet the stricter criteria.
  • Three conditions are commonly mistaken for insomnia: delayed sleep-wake phase disorder, obstructive sleep apnea, and just not allowing enough time in bed. Each is treated differently.

AASM = American Academy of Sleep Medicine

For education only, and not a substitute for advice from your own doctor or prescriber.

What insomnia is

  1. What Is Insomnia? Symptoms, Causes and TreatmentStart here

    Insomnia is not a number of hours. It is a specific pattern with specific criteria, and knowing them is the difference between a bad month and a treatable condition.

    7 min

  2. Insomnia Severity Index: What Your Score Means

    Seven questions, a score between 0 and 28, and four categories that help interpret the score. Here is where the score can be useful, and where its limitations lie.

    5 min

The symptoms, in the words people search

  1. How Long Should It Take to Fall Asleep?

    There is a widely quoted number for how long it should take to fall asleep: 30 minutes. Here is the context behind that number.

    5 min

  2. Why You Keep Waking Up at Night

    Everyone wakes in the night. The question is what happens in the minutes afterward.

    6 min

  3. Tired but Can't Sleep: What It Means

    Being tired and being sleepy are not the same state, and the gap between them is where this problem lives.

    5 min

  4. Is 6 Hours of Sleep Enough?

    There is an overall consensus recommendation of 7 hours a night, but the number of hours itself isn't the complete story.

    5 min

Who it affects, and when

  1. What Causes Insomnia in Women

    Women report insomnia symptoms more often than men. Does insomnia more commonly affect women, or is this merely a difference in reporting?

    4 min

  2. Insomnia During Pregnancy

    Insomnia during pregnancy is far more common than you would expect. Providers often hesitate to prescribe medication — and the first-line treatment for insomnia does not involve one.

    6 min

  3. Does Nicotine Cause Insomnia?

    Nicotine is a stimulant that wears off fast, which leaves your body in withdrawal overnight. Both halves of that equation affect sleep.

    5 min

What it is not

  1. Sleep Apnea vs Insomnia: How to Tell the Difference

    Two different conditions, two different treatments, and a large overlap that catches people out.

    5 min

  2. Delayed Sleep-Wake Phase Disorder: Is This Insomnia?

    Delayed sleep-wake phase disorder and chronic insomnia are often mistaken for each other. The answer to one question separates them, and getting it wrong can mean years of the wrong treatment.

    6 min

Do I have insomnia?

See if you have insomnia and learn how to sleep well again

2-min insomnia quiz

Common questions

How is insomnia diagnosed?
Clinically, against the ICSD criteria: a sleep difficulty, a daytime consequence, at least three nights a week, for at least three months, with adequate opportunity to sleep, and not solely due to another disorder or a substance. There is no test — no blood work, no scan, no wearable reading settles it.
What counts as difficulty sleeping?
None. There is no hours threshold in the diagnostic criteria. Two people can sleep the same number of hours and only one of them has insomnia, because the diagnosis rests on difficulty plus daytime impact rather than on total sleep time.
Can a questionnaire diagnose insomnia?
No. It measures how severe the problem seems to you and how much it is affecting your days. A diagnosis of chronic insomnia disorder additionally requires that symptoms occur at least three times a week, have lasted at least three months, are not explained by inadequate opportunity to sleep, and are not solely due to another disorder or a substance.
What else looks like insomnia?
Three things mainly. Delayed sleep-wake phase disorder, where sleep is normal on your own schedule and only broken on the world's. Obstructive sleep apnea, which fragments sleep and often presents with night-time waking. And insufficient sleep opportunity — not actually being in bed long enough — which the diagnostic criteria explicitly exclude.
How common is insomnia?
Around 30–36% of adults report at least one insomnia symptom, and roughly 6–10% meet the stricter diagnostic criteria. In the AASM's 2024 survey of 2,006 US adults, 12% said they had been diagnosed with chronic insomnia.

References

  1. Insomnia chapter, International Classification of Sleep Disorders, Third Edition, Text Revision (ICSD-3-TR). American Academy of Sleep Medicine; 2023.
  2. Chronic Insomnia. StatPearls, NCBI Bookshelf.
  3. Survey shows 12% of Americans have been diagnosed with chronic insomnia. American Academy of Sleep Medicine, 14 June 2024.
  4. Obstructive Sleep Apnea. StatPearls, NCBI Bookshelf.
  5. Auger RR, et al. Clinical practice guideline for the treatment of intrinsic circadian rhythm sleep-wake disorders. An update for 2015. Journal of Clinical Sleep Medicine. 2015;11(10):1199-1236.
  6. Schutte-Rodin S, Broch L, Buysse D, Dorsey C, Sateia M. Clinical guideline for the evaluation and management of chronic insomnia in adults. Journal of Clinical Sleep Medicine. 2008;4(5):487-504. doi:10.5664/jcsm.27286