is a self-administered questionnaire with 8 questions. It provides a measure of your general level of daytime sleepiness, or your average sleep propensity in daily life. It has become the world standard method for making this assessment.
The total ESS score provides an estimate of a general characteristic of you – namely, your average level of sleepiness in daily life. This can be influenced by many factors, and the ESS does not distinguish which factor(s) have caused any particular level of daytime sleepiness. It is not a diagnostic tool in itself, but is a very useful tool for measuring one important aspect of your sleep-wake health status.