Glasgow Coma Scale: How to Score and Document It

The Glasgow Coma Scale (GCS) is a structured way to describe a patient’s level of consciousness. It is not simply a score out of 15. The clinically useful information sits in the three separate components: eye opening, verbal response and motor response.

A total score can help summarise the assessment, but two patients with the same total may have very different patterns of neurological impairment. For that reason, the components should be assessed and documented separately, for example E3 V4 M6 = GCS 13/15.

GCS does not diagnose the cause of reduced consciousness. It should sit within a wider assessment that includes an ABCDE assessment, pupil assessment, limb movement, blood glucose where appropriate and review of possible causes such as head injury, stroke, seizure, hypoxia, infection, medicines or metabolic disturbance.

What does the Glasgow Coma Scale actually measure?

The GCS describes the patient’s best observed response in three domains:

• Eyes: whether the patient opens their eyes spontaneously or in response to sound or pressure.
• Verbal: the quality of the patient’s speech and orientation.
• Motor: the patient’s best motor response, from obeying commands through to no response.

The current structured approach is simple: check, observe, stimulate, rate. Before scoring, identify anything that could interfere with the assessment. Then observe what the patient is already doing. If needed, use sound and then an appropriate physical stimulus before assigning the best response seen.

Before you start: check for factors that can distort the score

Before assigning any number, ask whether the patient is actually able to demonstrate the response you are testing. This matters because a low score caused by an assessment barrier is not the same as a low score caused by neurological impairment.

Important confounders include:

• intubation or tracheostomy
• sedation or recent anaesthetic drugs
• neuromuscular blockade
• facial or orbital swelling
• aphasia or dysphasia
• hearing impairment
• language differences
• learning disability or developmental stage
• spinal cord or peripheral limb injury
• alcohol or other intoxicants

If a component cannot genuinely be assessed, use the documentation method required by the local chart. The modern GCS guidance uses NT, not testable, rather than automatically assigning a score of 1. If one component is NT, document the component and the reason it cannot be tested rather than calculating a misleading total.

A practical sequence at the bedside

Think of the assessment as a sequence rather than three unrelated number lists.

1. Observe first. Are the patient’s eyes already open? Are they speaking? Are they moving spontaneously?
2. Use sound. Speak clearly and give a simple request.
3. Use physical stimulation only if required. Use the method taught locally and only within your level of competence.
4. Rate the best response observed. Score eyes, verbal and motor separately.
5. Compare with the previous assessment. A change matters more than an isolated number.

Eye response: E4 to E1

E4: spontaneous

The patient opens their eyes without any verbal or physical stimulus. If the eyes are already open when you approach, that is spontaneous eye opening.

E3: to sound

The eyes are not open spontaneously, but they open after a spoken or louder verbal request.

E2: to pressure

The eyes open only after an appropriate physical pressure stimulus.

E1: none

There is no eye opening despite appropriate assessment and there is no local factor preventing the eyes from opening.

Teaching point: swollen eyelids are not the same as E1. If swelling physically prevents eye opening, the eye component may be NT.

Verbal response: V5 to V1

V5: orientated

The patient can communicate appropriately and correctly identifies key orientation information such as their name, location and date or time context.

V4: confused

The patient can hold a coherent conversation but is disorientated or confused. They may answer some questions correctly and others incorrectly.

V3: words

The patient produces recognisable words, but there is no sustained coherent conversation.

V2: sounds

The patient makes sounds such as moaning or groaning, but no recognisable words are produced.

V1: none

There is no audible verbal response and no factor preventing speech.

Common trap: an intubated patient has not demonstrated V1 in the same way as a patient who is physically able to speak but makes no sound. Record the verbal component as not testable according to local policy rather than forcing an inaccurate score.

Motor response: M6 to M1

The motor component is usually the part students find hardest because the difference between localising, normal flexion and abnormal flexion is not obvious until you have seen it assessed properly.

M6: obeys commands

The patient follows a simple command that they can reasonably understand and perform.

M5: localises

The patient purposefully moves a hand towards the site of the stimulus and attempts to remove or stop it. This is a directed response, not simply withdrawal of the limb.

M4: normal flexion

The limb flexes away from the stimulus, but the hand does not purposefully move towards the site of stimulation. This is normal flexion, sometimes described clinically as withdrawal.

M3: abnormal flexion

The arm shows an abnormal flexion pattern in response to stimulation. The movement is stereotyped rather than a purposeful attempt to localise or withdraw normally.

M2: extension

The arm extends in response to stimulation.

M1: none

No motor response is observed and there is no factor preventing movement.

Localising versus withdrawing: the distinction students often miss

If a patient simply pulls an arm away from pressure, that is not automatically localising. Localising is purposeful. The hand moves towards the site of the stimulus, usually in an attempt to remove it.

If the limb flexes away without the hand moving purposefully towards the stimulus, that is more consistent with normal flexion. Abnormal flexion is a stereotyped pathological response and should not be guessed from a brief or unclear movement. If you are unsure, assess with a registered practitioner.

This is one of the reasons motor scoring should be practised with a competent registered practitioner rather than learned from a table alone.

About physical stimulation

Physical stimulation should only be used when needed and according to local training. The structured GCS approach includes fingertip pressure and, where central stimulation is required, trapezius or supraorbital pressure.

Forceful sternal rubbing is discouraged because it can cause bruising and may produce responses that are difficult to interpret. As a student, do not improvise techniques you have not been taught. Ask your supervisor to demonstrate the approved method and observe your technique.

How to document a GCS properly

Do not write only “GCS 12”. That loses information.

Instead write the component scores:

E3 V4 M5 = GCS 12/15

Then add anything that affects interpretation, such as:

• time of assessment
• baseline or previous score
• pupil findings
• sedation or recent medicines
• intubation or communication barrier
• limb weakness or injury
• who was informed if the score changed

NICE specifically recommends communicating the three separate GCS responses when monitoring people with head injury, rather than relying on the total alone.

Worked example 1: confused but following commands

You approach a patient after a fall. Their eyes are already open. They can tell you their name and that they are in hospital, but they give the wrong month. They follow a request to squeeze and release your hand.

• Eyes: spontaneous = E4
• Verbal: confused = V4
• Motor: obeys commands = M6

Document: E4 V4 M6 = GCS 14/15.

The important finding is not simply “14”. The verbal component is reduced, so you would compare this with baseline, complete the wider neurological assessment and escalate any new change.

Worked example 2: the verbal score cannot be tested

A ventilated patient opens their eyes to voice and obeys commands. Because an endotracheal tube prevents speech, the verbal component cannot be assessed normally.

• Eyes: E3
• Verbal: NT because of intubation
• Motor: M6

Do not automatically write V1 and calculate a low total as though the patient had failed to produce speech despite being able to do so. Document the individual components and the reason the verbal component is not testable.

Worked example 3: why trend matters

A patient was documented one hour ago as E4 V5 M6. On reassessment they are E3 V4 M6.

The total has fallen from 15 to 13, but the important clinical information is that eye opening and verbal response have both deteriorated. That change requires prompt reassessment and escalation rather than waiting to see whether the score falls further.

GCS is only one part of neurological assessment

For a patient with reduced consciousness, also think about:

• ABCDE stability
• pupil size, equality and reaction
• limb strength and symmetry
• blood glucose
• oxygenation and ventilation
• recent seizure activity
• head injury or stroke symptoms
• sedatives, opioids and other medicines
• infection, shock and metabolic causes

In people admitted for head injury observation, NICE identifies GCS, pupil size and reactivity, limb movements, respiratory rate, heart rate, blood pressure, temperature and oxygen saturation as minimum neurological observations.

When should a change worry you?

A new reduction in consciousness is clinically important even if the patient still has a relatively high total score. Escalate promptly if you identify:

• a fall from the patient’s previous GCS
• new confusion or drowsiness
• new asymmetry in motor response
• new pupil abnormality
• seizure activity
• new focal neurological signs
• reduced consciousness alongside airway, breathing or circulation compromise

Follow the local escalation pathway and use a structured handover such as SBAR. If the patient is newly less responsive or a component has deteriorated, escalate the change rather than waiting for the total score to fall further.

Common GCS mistakes

• Recording only the total score.
• Scoring what you think the patient could do rather than what you actually observed.
• Using a physical stimulus before first observing and using sound.
• Calling withdrawal “localising” when the movement is not purposeful.
• Assigning V1 to an intubated patient without documenting the assessment barrier.
• Scoring swollen eyes as E1 when the eyes cannot physically open.
• Ignoring sedation, intoxication, language or hearing as confounders.
• Repeating harmful stimulation unnecessarily.
• Looking only at the total and missing deterioration in a single component.

Your role as a student nurse

You are expected to learn how to recognise and report neurological change, but you should use the chart and technique approved by your placement area. Practise the assessment with supervision until you are confident that you can distinguish the responses reliably.

If you are unsure whether a motor response is localising, normal flexion or abnormal flexion, ask a registered practitioner to assess the patient with you. If a patient’s level of consciousness has fallen, prioritise reassessment and escalation rather than trying to perfect the score independently.

The value of the Glasgow Coma Scale is not in memorising 4, 5 and 6. It is in observing the patient carefully, using a consistent method and communicating change clearly.

References

Glasgow Coma Scale (n.d.) The Glasgow Structured Approach to Assessment of the Glasgow Coma Scale. Institute of Neurological Sciences, NHS Greater Glasgow and Clyde. Available at: https://www.glasgowcomascale.org/

National Institute for Health and Care Excellence (NICE) (2023) Head injury: assessment and early management. NICE guideline NG232. Available at: https://www.nice.org.uk/guidance/ng232

Teasdale, G. and Jennett, B. (1974) ‘Assessment of coma and impaired consciousness: a practical scale’, The Lancet, 304(7872), pp. 81 to 84. Available at: https://doi.org/10.1016/S0140-6736(74)91639-0