Glasgow Coma Scale Calculator

The GCS was published by Graham Teasdale and Bryan Jennett at the University of Glasgow Institute of Neurological Sciences in The Lancet on July 13, 1974 ("Assessment of coma and impaired consciousness. A practical scale."). They built it to replace the vague language of "semi-comatose" and "obtunded" with three reproducible bedside observations: eye opening, verbal response, and motor response. The 3 to 15 total has been the de facto grading system for traumatic brain injury for fifty years and is embedded in the ATLS primary survey, the WHO injury surveillance dataset, and most ICU sedation protocols.

No. A low or falling GCS signals serious impaired consciousness, but the score alone does not determine airway treatment. Clinicians also assess breathing, airway reflexes, injury pattern, intoxication, sedation, seizures, and how the score changes over time. Use GCS to communicate observed responses, not as a stand-alone treatment instruction.

The common descriptive bands are severe at 3 to 8, moderate at 9 to 12, and mild at 13 to 15. They summarize observed consciousness and help teams communicate, but they do not prescribe imaging, airway treatment, consultation, or disposition by themselves. Cause, trend, pupils, vital signs, medications, sedation, and the rest of the examination all affect interpretation.

Eye opening and motor responses use the same numeric ranges, while the pediatric verbal subscale uses age-appropriate behaviors for children who cannot speak. The total still ranges from 3 to 15. Pediatric scores require developmental and clinical context, and the total alone does not determine airway treatment. Toggle the patient type to use the matching verbal descriptions.

An intubated patient cannot speak, so the verbal subscale collapses to 1 (often annotated GCS "E_V1T_M_") and the total drops artificially by up to 4 points. Sedation, paralytics, alcohol intoxication, aphasia, profound hearing loss, and orbital trauma all corrupt one or more subscales in the same way. In ICU practice the FOUR score (Full Outline of UnResponsiveness, Wijdicks 2005) is preferred for intubated patients because it adds a brainstem reflex subscale and a respiration pattern subscale and drops the verbal component entirely. For depth of sedation specifically, the Richmond Agitation-Sedation Scale (RASS) or Riker Sedation-Agitation Scale is the standard tool. Treat a GCS in any of these populations as a rough trend marker, not a hard number.