About

The Glasgow Coma Scale (GCS) serves as the clinical standard for assessing the level of consciousness in patients with acute brain injury. Originally developed in 1974 by Teasdale and Jennett, this scoring system objectively quantifies the degree of neurological impairment. Medical professionals utilize the GCS to monitor trends in a patient's condition, specifically looking for deterioration or improvement over time. The scale evaluates three aspects of responsiveness: Eye opening, Verbal response, and Motor response. The final score ranges from 3 (indicating deep coma or death) to 15 (indicating full consciousness).

Accurate calculation is vital for triage decisions, particularly in traumatic brain injury (TBI) cases. A score of 8 or less typically necessitates intubation for airway protection. Inconsistent scoring between providers can lead to miscommunication regarding the patient's status. This tool enforces the structured criteria defined by the Brain Trauma Foundation to ensure assessment consistency. It distinguishes between distinct motor responses (e.g., withdrawal versus abnormal flexion) which carry significant prognostic weight.

Formulas

The total Glasgow Coma Scale score is the summation of the best response in each of the three categories. The lowest possible score is 3 (1 in each category), and the highest is 15.

GCS = E + V + M

Severity Classification:

{

Severe TBI if GCS ≤ 8Moderate TBI if 9 ≤ GCS ≤ 12Mild TBI if GCS ≥ 13

Reference Data

Category	Response	Score	Clinical Definition
Eye Opening (E)	Spontaneous	4	Eyes open without stimulation.
	To Sound	3	Eyes open to verbal command or shout.
	To Pressure	2	Eyes open to physical pressure (fingertip/trapezius).
	None	1	No eye opening at any time.
Verbal Response (V)	Oriented	5	Correctly gives name, place, and date.
	Confused	4	Converses but is disoriented.
	Words	3	Intelligible single words, random exclamations.
	Sounds	2	Moans/groans, no intelligible words.
	None	1	No audible sound, even with painful stimulus.
Motor Response (M)	Obey Commands	6	Performs two-part request (e.g., lift hand, squeeze).
	Localising	5	Moves hand above clavicle to remove stimulus.
	Normal Flexion	4	Rapid flexion, arm pulls away from stimulus.
	Abnormal Flexion	3	Decorticate posturing (slow flexion, wrist rotation).
	Extension	2	Decerebrate posturing (arm extends, internal rotation).
	None	1	No movement in arms/legs, flaccid.

Frequently Asked Questions

If a patient is intubated, the Verbal component cannot be tested. In clinical practice, the score is often recorded as the sum of Eye and Motor with the suffix "T" (e.g., E2M4T) or the Verbal score is marked as "NT" (Not Testable). This calculator assigns a baseline value of 1 for calculation purposes but users should note the limitation in medical records.

This is a common point of confusion. Normal flexion (Withdrawal, M4) involves a rapid movement where the arm pulls away from the painful stimulus. Abnormal flexion (Decorticate, M3) is slower, often accompanied by adduction of the shoulder and rotation of the wrist toward the chest.

The scale assigns a minimum of 1 point for "None" in each of the three categories (Eye, Verbal, Motor). Therefore, the mathematical minimum is 1 + 1 + 1 = 3. A score of 0 is not possible in the standard GCS model.

The standard GCS is used for adults. For children under 5 years old, specifically pre-verbal infants, the Pediatric Glasgow Coma Scale (pGCS) is utilized, which adjusts the Verbal criteria to account for crying and interaction levels appropriate for age.

If eye swelling prevents the patient from opening their eyes (even if they are awake), the Eye component is considered "Not Testable" (NT). Often, clinicians score it as 1 for calculation but document the physical obstruction clearly (e.g., E1c where c = closed due to swelling).