Glasgow Coma Scale (GCS)

Evaluates the level of consciousness following traumatic brain injury by considering the eye, verbal and motor response.

There is in depth information, below the tool, about the scale and the original study.

As a universally used method of consciousness assessment, GCS requires an evaluation of eye opening, verbal and motor response.

The scale is used in clinical settings all over the world to evaluate the conscious state of patients with or suspect of brain injury.

The below Glasgow Coma Scale calculator provides the GCS in an easy to calculate form.

The scale results vary from 3 to 15, the higher the scale, the more increased level of consciousness.

Observations are recorded every half hour after admission and for two more hours when the scale reaches 15.

After this, observations are taken every hour for the next 4 hours and then 2 hourly until discharge.

GCS of 8 or less may require intubation.

The following table introduces brain injury classification according to GCS scores:

GCS score Brain injury
3 - 8 Severe injury
9 - 12 Moderate injury
13 - 15 Minor injury


Eye opening


Verbal response


Motor response

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Steps on how to print your input & results:

1. Fill in the calculator/tool with your values and/or your answer choices and press Calculate.

2. Then you can click on the Print button to open a PDF in a separate window with the inputs and results. You can further save the PDF or print it.

Please note that once you have closed the PDF you need to click on the Calculate button before you try opening it again, otherwise the input and/or results may not appear in the pdf.


Glasgow Coma Scale items

The scale is brief and simple to use, thus being favoured in ER departments and intensive care units ICU for evaluation both trauma and non-trauma presentations.

There are three questions, each within a different nervous response area.

Glasgow Coma Scale (GCS)
Types of response Degrees Points
Eye opening spontaneous opening 4
eye opening to auditive stimulus e.g. speech 3
eye opening to pain stimulus e.g. squeezing the top of a finger 2
no eye opening 1
Verbal response oriented responses with the patient being coherent and answering appropriately 5
confused answering with the patient disoriented 4
inappropriate words with the patient saying words but not sentences 3
incomprehensible sounds 2
no verbal response 1
Motor response conscious obeying of the motor commands given 6
movement towards pressure/ pain stimulus 5
withdrawal from pain/ pressure stimulus 4
flexor reaction 3
extensor reaction 2
no motor response 1

The scale is used to assess both the current state and predict patient progression. Observations are recommended to be taken at certain intervals:

■ Before GCS reaches 15: every half hour;

■ After GCS reaches 15: every half hour for first 2 hours, then hourly for next 4 hours, then 2 hourly until discharge;

■ In case GCS drops again below 15, half hourly observations are to be established again.


GCS interpretation

The points awarded to each of the three answers selected are summed to provide the GCS score.

The maximum of points obtainable for each question is:

■ Eye opening – maximum 4 points;

■ Verbal response – maximum 5 points;

■ Motor response – maximum 6 points.

This can vary between 3 and 15, where 3 is the lowest and 15 is the highest level of consciousness.

A GCS score of 3 means: no eye opening, no verbalization and no response to pain stimuli. A GCS of 15 means: spontaneous eye opening, oriented responses with the patient being coherent and answering appropriately and conscious obeying of the motor commands given.

GCS scores of 8 and less have been found more likely to require intubation.

The following table introduces the three levels of brain injury and their characteristics:

GCS score Brain injury severity Characteristics and consequences
3 - 8 Severe Long term cognitive and physical impairment with emotional and behavioural changes.
9 - 12 Moderate Long term cognitive and physical impairment.
13 - 15 High Temporary or permanent neurological effects but sometimes no imagistic evidence of brain damage.

About the original study

The scale was described by Graham Teasdale and Bryan Jennett, in 1974 in the journal article: Assessment of coma and impaired consciousness. A practical scale.

The GCS was aimed at monitoring trends in responsiveness. The list of terms used has been refined through inter-observer studies.

In 1980 it was recommended in the first edition of the Advanced Trauma and Life Support and the World Federation of Neurosurgical Societies (WFNS) also used it in its scale for subarachnoid haemorrhage.

Sir Graham Teasdale was President of the Society of British Neurological Surgeons amongst other titles, was made Knight Batchelor in 2006 for services of Neurosurgery and has received Medal of Honour of the World Federation of Neurosurgical Societies, amongst other accolades.

Bryan Jennett CBE was Professor of neurosurgery at Glasgow University and contributed to the description of the Persistent Vegetative State (1972) and creation of the Glasgow Coma Scale (1974) and Glasgow Outcome Scale (1975).


Original source

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


Reith FC, Van den Brande R, Synnot A, Gruen R, Maas AI. The reliability of the Glasgow Coma Scale: a systematic review. Intensive Care Med. 2016; 42(1):3-15.

Other references

1. Sternbach GL. The Glasgow coma scale. J Emerg Med. 2000; 19(1):67-71.

2. The Glasgow Structured Approach to Assessment of the GLASGOW COMA SCALE.

Specialty: Emergency

System: Nervous

Objective: Evaluation

Type: Scale

No. Of Items: 3

Year Of Study: 1974

Abbreviation: GCS

Article By: Denise Nedea

Published On: March 15, 2017

Last Checked: March 15, 2017

Next Review: March 9, 2023