How does the Glasgow Coma Scale work?
To get your Glasgow Coma Scale score, providers take the scores from the three categories of the GCS and add them together. A healthcare provider will test each of the three categories in multiple ways. An example of this is testing your verbal response by asking you a few different questions, such as what day of the week or date it is or what city you're in currently.
One of the best uses of the GCS is to track changes in your level of consciousness. Healthcare providers will often repeat a neurological exam at regular intervals to check for and document any changes in your GCS score.
The scoring guidelines for the categories are as follows:
Eye response
This is mainly about how awake you are. If you’re unconscious, it measures the level of unconsciousness by testing reflex responses to pressure. Pressure here means something like a pinch or a poke. It should be just enough to cause minor, momentary discomfort but not injury.
| Eye response score | Score meaning |
|---|---|
| 4 | You can open your eyes and keep them open on your own. |
| 3 | You only open your eyes when someone tells you to do so. Your eyes stay closed otherwise. |
| 2 | Your eyes only open in response to feeling pressure. |
| 1 | Your eyes don’t open for any reason. |
| Eye response score | |
| 4 | |
| Score meaning | |
| You can open your eyes and keep them open on your own. | |
| 3 | |
| Score meaning | |
| You only open your eyes when someone tells you to do so. Your eyes stay closed otherwise. | |
| 2 | |
| Score meaning | |
| Your eyes only open in response to feeling pressure. | |
| 1 | |
| Score meaning | |
| Your eyes don’t open for any reason. |
Verbal response
A provider checks this by asking you questions that test your memory, thinking ability and your awareness of the world around you. Your provider can also use this to see if there are any brain or nerve problems affecting control of your face and mouth.
| Verbal response score | Score meaning |
|---|---|
| 5 | You’re oriented. You can correctly answer questions about who you are, where you’re at, the day or year, etc. |
| 4 | You’re confused. You can answer questions, but your answers show you’re not fully aware of what’s happening. |
| 3 | You can talk and others can understand words you say, but your responses to questions don’t make sense. |
| 2 | You can’t talk and can only make sounds or noises. |
| 1 | You can't speak or make sounds. |
| Verbal response score | |
| 5 | |
| Score meaning | |
| You’re oriented. You can correctly answer questions about who you are, where you’re at, the day or year, etc. | |
| 4 | |
| Score meaning | |
| You’re confused. You can answer questions, but your answers show you’re not fully aware of what’s happening. | |
| 3 | |
| Score meaning | |
| You can talk and others can understand words you say, but your responses to questions don’t make sense. | |
| 2 | |
| Score meaning | |
| You can’t talk and can only make sounds or noises. | |
| 1 | |
| Score meaning | |
| You can't speak or make sounds. |
Motor response
This part can reveal any issues with the connections between your nerves, spinal cord and brain. It also tests your brain’s ability to control muscle movement and how well you can understand and follow instructions.
| Motor (movement) response score | Score meaning |
|---|---|
| 6 | You follow instructions on how and when to move. |
| 5 | You intentionally move away from something that presses on you. |
| 4 | You only move away from something pressing on you as a reflex. |
| 3 | You flex muscles (pull inward) in response to pressure. |
| 2 | You extend muscles (stretch outward) in response to pressure. |
| 1 | You don’t move in response to pressure. |
| Motor (movement) response score | |
| 6 | |
| Score meaning | |
| You follow instructions on how and when to move. | |
| 5 | |
| Score meaning | |
| You intentionally move away from something that presses on you. | |
| 4 | |
| Score meaning | |
| You only move away from something pressing on you as a reflex. | |
| 3 | |
| Score meaning | |
| You flex muscles (pull inward) in response to pressure. | |
| 2 | |
| Score meaning | |
| You extend muscles (stretch outward) in response to pressure. | |
| 1 | |
| Score meaning | |
| You don’t move in response to pressure. |
GCS-P
In 2018, a team of experts — including one of the original creators of the GCS — published an updated version of the GCS called the “GCS-P.” The P stands for “pupil,” as in the pupil of the eye. This is a fourth number that providers subtract from the standard GCS score.
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Pupil reaction is important because it’s an indicator of your brain function. When your pupils don’t react to light, it’s a sign that a serious problem or injury is affecting your brain. The pupil score ranges from 0 to 2.
The pupil scores mean:
- 2: Neither pupil reacts to light.
- 1: One pupil doesn’t react to light.
- 0: Both pupils react to light.
Subtracting the pupil reaction score from the GCS score means that the GCS-P score can range from 1 to 15. The GCS-P score still uses a score of 8 or fewer to mean a coma.
A GCS score of 3 and a pupil score of 2 is a GCS-P score of 1. That means a very deep coma and no pupil reaction in both eyes.
Does a neurological exam that uses the Glasgow Coma Scale involve pain?
Older descriptions of the GCS use the word “pain” to describe the sensation used to test certain reflexes. Newer guidelines change that word to “pressure.” The word change is more accurate because it doesn’t involve an injury. It’s also clearer because a provider isn’t actually trying to cause pain or hurt your loved one.
The original GCS guidelines were also vague on where providers should press to test reflexes. In 1975, a year after the original publication of the GCS, the experts who created the GCS published specific guidance. Points where a provider will put pressure include your:
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- Nail beds: Your fingernails and toenails are pressure-sensitive. Providers often push on one or more of them during a neurological exam to test if your body reacts reflexively to the pressure.
- Trapezius muscle: This muscle connects your shoulder to the center of your neck and back. It’s an easy-to-reach muscle to check for a pressure reflex.
- Supraorbital notch: This is a small groove in the bone of your skull just above your eye and just below your eyebrow.
