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ReSomnia

Guide · 6-minute read

Do I have insomnia? The signs to take seriously

Insomnia is called chronic when sleep difficulties occur at least three nights a week for at least three months, and affect your days[1]. To see where you stand in two minutes, the ISI test gives a score from 0 to 28 that shows how severe your difficulties are[3].

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By Andy Leleux, sleep technologist · Updated on 27 October 2026

Key points

  • Three criteria: sleep difficulties at least three nights a week, for at least three months, with an impact on your days[1].
  • Insomnia is not defined by how many hours you sleep, but by difficulty sleeping and what it does to you.
  • The ISI test measures severity in 7 questions; it does not replace a professional opinion[3][4].
  • Snoring with pauses in your breathing, or severe sleepiness: talk to your doctor, because it may not be (only) insomnia.

The signs of insomnia

Insomnia can take three forms, which often overlap:

  • Trouble falling asleep: you toss and turn, your mind racing, unable to switch off.
  • Waking in the night and struggling to get back to sleep (see waking up at night).
  • Waking too early in the morning, with no way of getting back to sleep.

These difficult nights carry over into the day: tiredness, trouble concentrating or remembering things, irritability, low mood, worry as bedtime approaches. This impact is what separates insomnia from simply being a “short sleeper” who feels fine on little sleep[1].

A run of bad nights or chronic insomnia?

Everyone has bad nights: before an exam, after a bereavement, during a stressful spell. Sleep usually returns by itself once things calm down.

Insomnia is called chronic when the difficulties occur at least three nights a week, for at least three months, even though you have the time and the right conditions to sleep, and they affect your days[1]. By this stage, insomnia often sustains itself, through the habits you have picked up to compensate and through worry about sleep.

Why three months?

This is the threshold international classifications use for chronic insomnia. And chronic insomnia is the condition for which CBT-I is recommended first[1][2].

See where you stand with the ISI test

The Insomnia Severity Index (ISI) is the standard questionnaire, used by doctors and in research alike. Its 7 questions cover the past two weeks and give a score from 0 to 28[3][4]:

  • 0 to 7: no clinical insomnia.
  • 8 to 14: subthreshold (mild) insomnia.
  • 15 to 21: moderate insomnia.
  • 22 to 28: severe insomnia.

The score is not a diagnosis: it helps you put words and numbers to what you are going through, and talk about it with a professional. Repeated every few weeks, it also lets you track how things are changing.

What can look like insomnia

Other conditions also disturb sleep, and are managed differently. A few signs should prompt you to talk to your doctor[1]:

  • Loud snoring, pauses in breathing noticed by someone close to you, severe daytime sleepiness: this could be sleep apnoea. The Epworth test measures your sleepiness; only a sleep study can confirm apnoea.
  • Unpleasant sensations in your legs in the evening, with an irresistible urge to move them: this could be restless legs syndrome.
  • Normal sleep at the wrong time (falling asleep very late, struggling to wake in the morning, but sleeping well when you can follow your own rhythm): this could be a shifted body clock.
  • Sadness or anxiety that does not lift: mood and sleep problems often feed each other, and both deserve proper care.

When to see a doctor

Talk to your doctor if your difficulties have lasted several weeks and affect your days, if you have been taking sleeping medication for a long time, or if you recognise any of the signs above.

Do not wait

If you fall asleep at the wheel or in the middle of an activity, see a doctor promptly and avoid driving. If difficult thoughts are taking over, call at any time: 1813 (in Dutch) or 0800 32 123 in Belgium, 116 123 in the UK and Ireland, 988 in the US, or 112 or your local emergency number if you are in danger.

What next?

If your difficulties fit chronic insomnia, European and American guidelines recommend cognitive behavioural therapy for insomnia (CBT-I) as the first treatment, before sleeping pills[1][2]. You can follow it with a trained clinician, with a digital programme, or both.

To begin, a sleep diary kept for one to two weeks shows your real sleep times and your sleep efficiency: this is the starting point of CBT-I.

Frequently asked questions

Can you have insomnia and still sleep seven hours?

Yes (see how much sleep you really need). Insomnia is not defined by a number of hours, but by difficulty sleeping (falling asleep, staying asleep, waking too early) and its effect on your days. Equally, some people sleep little without complaint or tiredness: that is not insomnia.

Is it normal to wake up during the night?

Brief awakenings are part of normal sleep and often go unnoticed. They become a problem when they are long, when sleep does not come back, when it happens several nights a week and your days suffer for it.

Does the ISI test give a diagnosis?

No. It shows how severe your difficulties have been over the past two weeks. Only a professional can make a diagnosis, taking your situation into account.

My ISI score is high: what should I do?

Talk to your doctor or a clinician trained in CBT-I. You can also start a sleep diary right away: it will be useful for the appointment and for the programme alike.

Can insomnia go away on its own?

Short-term insomnia linked to an event often disappears once things calm down. When it settles in, the habits you pick up to compensate (staying in bed longer, napping) can keep it going: these are the very habits CBT-I works on.

Read and do next

Sources

  1. [1] Riemann D, et al. The European Insomnia Guideline: an update on the diagnosis and treatment of insomnia 2023. J Sleep Res. 2023;32(6):e14035. PubMed
  2. [2] Edinger JD, et al. Behavioral and psychological treatments for chronic insomnia disorder in adults: an AASM clinical practice guideline. J Clin Sleep Med. 2021;17(2):255-262. PubMed
  3. [3] Morin CM, et al. The Insomnia Severity Index: psychometric indicators to detect insomnia cases and evaluate treatment response. Sleep. 2011;34(5):601-608. PubMed
  4. [4] Bastien CH, Vallières A, Morin CM. Validation of the Insomnia Severity Index as an outcome measure for insomnia research. Sleep Med. 2001;2(4):297-307. PubMed

This guide provides information and does not replace advice from a doctor or psychologist. If you are in distress, call your local crisis line at any hour: 1813 or 0800 32 123 in Belgium, 116 123 in the UK and Ireland, 988 in the US. In immediate danger, call 112 in Europe or your local emergency number.

See where you stand, then take action.

ReSomnia starts with your nights: a two-minute diary every morning, the ISI test to track your progress, and a six-week CBT-I programme, with your clinician if you wish.

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The app itself is in French for now. English is on the way.