Glasgow Coma Scale Explained

Whether for NREMT Test Prep or for general use on the truck, calculating GCS can be a pain. Let's see how much we can simplify it.

What is the Glasgow Coma Scale?

Think of GCS like an advanced method of AVPU; it's an accepted assessment tool for evaluating response ability.  It's primarily used in head trauma to convey the possible extent of injury. You can transfer a lot of information about your patient in a very short amount of time. It's like saying "this patient is responsive to pain, and also exhibits this specific type of response." The type of response, itself, is shorthand between providers that implies the severity of the injury or illness. Giving GCS in a radio report tells the hospital what they are likely to encounter upon your arrival.

A dead person has a GCS score of THREE, not ZERO! This seems counter-intuitive because we naturally think of ZERO as NONE. So, if the patient has NO EYE response, we assume the score would be zero. GUESS WHAT! IT SHOULD! The darn scale SHOULD go from 0-12 instead of 3-15. The scale is entirely arbitrary, and this change would make it easier to assimilate, would result in less errors and,thus, be more efficient. But, this is what we have, and it is, currently, the standard. So, we just have to deal.

You have to remember that the lowest number is 3. A dead person is GCS 3. A completely unresponsive person is GCS 3. A completely awake, oriented and normal person is a 15. These things you just have to dig into your head.  Now lets see why...

Breaking Down the Glasgow Coma Scale

Lets start with what we know: 3 = worst. 15 = best. Now, unless you want to memorize the whole chart or carry some card around you at all times, we have to come up with some ways to make it easier. We evaluate responsiveness in 3 categories: Eyes, Speech, and Motor. Lets say you have a GCS 12 patient. Just saying the score doesn't tell you that its E3, S4, M5... it just adds up the three categories to give you an overall picture of how bad the patient is. We're just using GCS to say "He's not that bad," "He's questionable," or "Man, he's really messed up."


The Standard GCS scale

GCS in Plain English:

We are assessing responsiveness because being able to react to stimuli means the brain is working.

MEMORY TOOL:  For GCS SCORING, Remember  1,2,3,4,5,6  (Three Questions and 3 Scores) 

There are 3 questions: 1) Do his eyes respond?  2) Does he verbally respond? 3) Does he respond with his body?

There are 3 max points: 4) Eyes get a max of 4 points, 5) verbal gets 5 points,  6) motor gets 6 points.

So, 1, 2, 3, 4, 5, 6

Instead of writing GCS score to begin with, just start PRACTICING with using E4, S5, M6.  Get in the habit of looking at a patient and judging his response. If he's totally responsive, he's E4, S5, M6. If he's a little confused, like after a concussion, but his eyes open and he has purposeful movements, then you only have to take 1 from speech. So the confused guy is E4, S4, M6. 

Use it like a checklist. Do his eyes open? If yes, then score a 4. If no, then score a 1. If "kinda," then look at the criteria. Same with the other 2. Check yes or no or kinda. If "kinda" then check out that specific list and proceed.

DO HIS EYES OPEN? (Max 4) (Eyes are easy, you're assessing eye AVPU)

  1. No matter what I do, his eyes don't open.
  2. Eyes open when I inflict pain
  3. Eyes open when I call his name
  4. Eyes are normally open


  1. He's not talking at all
  2. He's just making sounds
  3. He's saying words, but they don't make sense
  4. He's talking, but he's confused
  5. He's talking normally


  1. He's not moving, no matter what I do.
  2. If I apply pain, his body flexes away from his core. Extension.
  3. If I apply pain, his body tightens towards his core. Flexion.
  4. If I apply pain, his body tries to back away from the pain spot.
  5. If I apply pain, he moves his hand to the pain spot.
  6. He is moving on his own.

Special Considerations

Tracheal intubation and severe facial/eye swelling or damage make it impossible to test the verbal and eye responses. In these circumstances, the score is given as 1 with a modifier attached e.g. "E1c" where "c" = closed, or "V1t" where t = tube. A composite might be "GCS 5tc". This would mean, for example, eyes closed because of swelling = 1, intubated = 1, leaving a motor score of 3 for "abnormal flexion". Often the 1 is left out, so the scale reads Ec or Vt.




On the Truck

I DON'T recommend using it, on the truck, for awhile. During clinical rides, and during your first year, you will likely have to use a delegated memory tool to calculate it. If you have time to look at your GCS card, or look at your protocol book or an app, that's great. You probably won't have time, at first, so DON'T USE IT. You will probably spend more time looking it up than you will save by using it anyway, and your patient needs that extra time NOW. If they're totally unresponsive, you can say "GCS 3" and if they're totally normal, you can say "GCS 15." Just forget the numbers and just report on the 3 variables that matter in plain english. Example: Eyes are closed. No speech. He is only pulling away from pain. So, in short, REPORT what you SEE and FORGET about the numbers at first. Over time, you will start to associate the levels more clearly with numbers out of habit, but if you don't, who cares? You can look it up if you need it.

For the Test and Giving Reports

Because you can't use delegated memory like cards or apps on tests, it seems like you have to memorize this whole thing. You certainly can, but I don't advise it. During school and your rookie year, you should spend AS MUCH of your STUDY time learning concepts, ACLS or BLS algorithm, and WHY you're doing what you're doing. Instead, I recommend learning these few, as they are most likely to be found on the tests and important in your report.

GCS 3:  Completely unresponsive. Total coma. There are a lot of test questions that really just want to know if you understand that 3 is the bottom.

GCS 15:  Almost all (73% of patients) are GCS 15. You can practice saying this on all normal patients. Patient opens eyes, speech is fine, and moves on his own.

GCS 14: The patient is confused. This is another very common one to have on hand. (Dementia, intoxication, concussion?)

GCS 13: Talking out of his head. (bleed?)

GCS <8: This usually means the patient is non-verbal, eyes are closed, and only has some basic response to pain. So, eyes and speech are a 1, and you're just evaluating his motor response. Generally, if a patient doesn't have good control over his motor function, it indicates severe damage and that he may not be able to control his own airway.

REMEMBER THE NUMBERS - Eye goes up to 4, Speech goes up to 5, motor goes up to 6.

If you know those 6 things, AND NOTHING ELSE, you're going to be able to answer 90+ percent of the GCS questions on the test correctly! So, if you have time to memorize it all before the test, go nuts. If you don't, get back to those algorithms!

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