The Glasgow Coma Scale is the most widely used method of grading Traumatic Brain Injury severity. The scale ranges from 3-15, with 3 being the most severe condition and 15 being normal. When combined with duration of loss of consciousness and presence or absence of posttraumatic amnesia, the Glasgow coma score can also be used to predict outcome.

The system involves 3 areas of testing: Eye, Verbal, Motor (EVM) or, with grading E4,V5, M6).

First, opening of the eyes. 4-eyes open spontaneously and with purpose, 3- eyes open to verbal stimuli, 2 eyes open to pain or pressure, 1-no response.

Second, verbal response. 5-oriented, 4-confused but conversant, 3-random inappropriate words, 2-incomprehensible sounds, 1-non verbal

Third, motor response. 6-obeys commands, 5-localizes pain, 4-withdraws from pain, 3-flexion of arms in decorticate pattern (arms flexed at elbows across chest bilaterally and flexed at wrists), 2-decerebrate posturing (arms extended fully at side with wrists pronated), 1-no observable motor response to stimulation.

13-15 is mild Traumatic Brain Injury, 9-12 is moderate Traumatic Brain Injury, and 3-8 is severe Traumatic Brain Injury and unable to protect airway (may need intubation).