Glasgow coma scale: definition


The GCS is the summation of scores for eye, verbal, and motor responses. The minimum score is a 3 which indicates deep coma or a brain-dead state. The maximum is 15 which indicates a fully awake patient (the original maximum was 14, but the score has since been modified).

For best eye responses, there are 4 possible scores:

  • No eye opening
  • Eye opening in response to pain. (i.e., pressure to fingernail bed or sternal rub)
  • Eyes opening to speech
  • Eyes opening spontaneously

For best verbal response, there are 5 possible scores:

  • No verbal response
  • Incomprehensible sounds (such as moaning)
  • Inappropriate words
  • Confused speech
  • Oriented

For best motor response, there are 6 possible scores:

  • No motor response
  • Extension to pain
  • Abnormal flexion to pain
  • Withdrawal to pain
  • Localizes to pain
  • Obeys commands

Once the individual eye, verbal, and motor responses are summed, the final score indicates the following level of brain injury:

  • Minor, GCS ≥ 13
  • Moderate, GCS 9 – 12
  • Severe, with GCS ≤ 8

There are also modifications to the score for intubated patients as well as pediatric patients, as their responses may not adequately grade their level of consciousness (i.e. a 6 month old cannot express themselves, nor can an intubated patient).

Keyword history

  • 90%/2009
  • 94%/2010
  • 99%/2012
  • 62%/2014


  1. G Teasdale, B Jennett Assessment of coma and impaired consciousness. A practical scale. Lancet: 1974, 2(7872);81-4 [PubMed:4136544]