Glasgow Coma Scale (GCS)
Calculate the Glasgow Coma Scale score from eye opening, verbal response, and motor response to assess level of consciousness.
Results
What is it?
DISCLAIMER: For educational and reference purposes only. All clinical decisions must be made by qualified healthcare professionals. The Glasgow Coma Scale (GCS), developed by Teasdale and Jennett in 1974, is the most widely used standardised tool for assessing level of consciousness after brain injury. It scores three components: Eye opening (E, 1-4), Verbal response (V, 1-5), and Motor response (M, 1-6). Maximum score is 15 (fully conscious); minimum is 3 (deep coma or death). Report as individual components (e.g., E3V4M5 = GCS 12) and total. TBI severity classification: Mild 13-15; Moderate 9-12; Severe 3-8. A GCS of 8 or less is a traditional threshold for airway protection (intubation).
How to use
Assess the patient and select the best response observed in each of the three domains. Always document the individual scores (E, V, M), not just the total, as this provides richer clinical information. For intubated patients, verbal score is recorded as V = T (intubated) and the total is adjusted.
Example scenario
Post-trauma patient: opens eyes to voice (E=3), confused speech (V=4), localises to pain (M=5). GCS = E3V4M5 = 12. This falls in the moderate TBI range (9-12). The clinical team will monitor for deterioration — a drop to 8 or below would prompt airway intervention.
Pro tip
Always use the best response observed and document time of assessment. Serial GCS measurements are more informative than a single score — a declining GCS over time is a more important clinical finding than the absolute number. In children under 5, a modified paediatric GCS scale should be used as verbal responses differ by developmental stage.