Insomnia Severity Index (ISI): sleep test explained
What is the Insomnia Severity Index?
The ISI asks about difficulties with sleep and how you experience their consequences. It is a self-report measure: you describe your own experience rather than having your sleep recorded in a laboratory. Completing it can provide a starting point for discussing a concern.
An online insomnia test cannot determine the cause of a sleep problem. A useful follow-up conversation explores when the difficulty began, what your schedule allows, and what else has been happening. Your own explanation matters alongside the number.
Can I use an insomnia test for exam stress?
Yes, sleep difficulties during exam season can be a reason to explore the ISI. However, it is not an exam anxiety test and cannot establish that exams caused your symptoms.
Consider two fictional students. One stays up revising until 2 a.m. and gets up at 7 a.m. The other leaves enough time for sleep but spends much of the night awake. Both deserve support, but their accounts raise different questions. A total alone cannot explain the difference.
If your main concern is worry across many situations, the GAD-7 may be a more relevant starting point. If it is feeling overwhelmed by life overall, explore the PSS-10. You do not need to complete every questionnaire before asking for help.
Which period should I think about?
Follow the instructions on the form you actually complete, and read its heading before you begin. Separate patient versions of the ISI exist for a two-week and a one-month recall period, so the timeframe is a property of the form in front of you rather than of the scale as a whole. Morin describes the last month as the standard recommended interval, and the university-hosted form linked below uses it.
When comparing results, record the version and recall period. A score covering a month of ordinary classes is not directly equivalent in context to one covering two weeks of final exams.
How should I use these explainers?
Start with the question that brought you here. The separate explainers describe the questionnaire without requiring you to take it first.
- Purpose: understand the difference between insomnia symptoms, tiredness, and short sleep.
- Structure: learn how to approach the response options and recall period.
- Scoring: check the calculation and the conventional score bands.
- Results: put the number in context and prepare a useful next step.
- Who it is for: consider age, language, and circumstances.
- Validity and reliability: understand what research supports and where uncertainty remains.
Where can I take the ISI online?
The assessment button opens LuriaLab, an external website. ExamStressCheck provides the educational explainers on these pages. Read the destination's instructions and privacy information before entering answers.
You can also bring a description of your sleep directly to a healthcare professional or student support service. An online result is optional; it is not a requirement for being taken seriously.
This page is educational. A questionnaire score cannot establish a diagnosis or explain the cause of your symptoms. If you are struggling, speak with a counselor or healthcare professional, whatever your score.
Read how to ask for support or find a helpline in your country.