ISI score meaning — how serious is your insomnia?

The Insomnia Severity Index helps measure sleep difficulty, satisfaction, daytime impact and distress. It is useful because people often normalise poor sleep until the score makes the pattern visible.

Mild insomnia may respond to routine changes. Moderate insomnia usually needs structured CBT-I style work. Severe insomnia, especially with depression, anxiety, pain or medication use, deserves clinical assessment. Duration matters: three bad nights and three bad months are different problems.

Fix wake time, reduce time awake in bed, move caffeine earlier, create a wind-down and stop clock watching. Repeat the ISI after two weeks. If there is no improvement, seek structured sleep treatment rather than adding random sleep hacks.

Urgent help is needed if insomnia comes with suicidal thoughts, mania-like energy, hallucinations, substance withdrawal or inability to function. Sleep is foundational; protect it early.