Insomnia does not always show up in ways that are easy to measure. Because sleep is a deeply personal experience, and how well you sleep cannot always be captured by numbers alone. So, how do doctors and sleep specialists assess something so subjective? They often turn to structured tools that bring more clarity to your sleep experience. One of the most widely used is the Insomnia Severity Index, a simple questionnaire designed to measure the impact of insomnia on your daily life.

Insomnia is not always easy to recognize, and many people live with it for months before realizing  something is problematic . In this article, we will discuss  the most common symptoms, possible causes, and how insomnia is assessed in clinical care.