The seriousness of an accident victim's head injury can be rated using the Glasgow Coma Scale.

What is the Glasgow Coma Scale?

The Glasgow Coma Scale (GCS), also known as Glasgow Coma Score, is a neurological scale that was designed to give doctors a reliable, objective way of recording the conscious state of someone that has suffered a head or brain injury.

A victim is assessed according to their abilities and physical responses in the "Area Assessed" column of the scale, and the resulting points give a patient a score between 3 (indicating deep unconsciousness) and 15 (indicating mild brain injury).

GCS was initially used to assess level of consciousness after a head injury, and the scale is now used by first aid, EMS and doctors as being applicable to all acute medical and trauma patients. In hospitals the scale is also used in chronic patient monitoring, such as those who are placed in the intensive care unit.

                                                                 

Area Asessed:   
Eye opening    
     
                                               
Open spontaneously:                       
   4      
         
Open to verbal command:                    3      
              
Open in response to pain applied        

to the limbs or sternum:                      2
       
None:                                              1      

Area Assessed:
Verbal 

Oriented:                                          5      
        
Disoriented, but able to answer           
questions:                                         4

         
Inappropriate answers to                    
questions; words discernible:                3
       
Incomprehensible speech:                    2
                
None:                                               1     

Area Assessed:
Motor

Obeys commands:                             6
   
Responds to pain with purposeful        
movement:                                       5

       
Withdraws from pain stimuli:                4
             
Responds to pain with abnormal         

flexion (decorticate posture):               3
       
Responds to pain with abnormal          
(rigid) extension (decerebrate posture): 2
    
None:                                               1     


TOTALS:

14 or 15 is mild TBI
9 to 13 is moderate TBI
3 to 8 is severe TBI

Combined scores < 8 are typically regarded as coma.