The Glasgow Coma Scale (GCS) describes the level of consciousness according to three response categories: eye opening, motor and verbal responses.

With good inter-observer reliability and ease of use, admission GCS has been associated with prognostic prediction for a number of conditions, including traumatic brain injury, subarachnoid hemorrhage, and bacterial meningitis.

The FOUR (Full Outline of UnResponsiveness) scale graduates the severity of the coma and can be more accurate

The RASS scale (Richmond Agitation-Sedation Scale) classifies agitation and the possibility of agitation.