Checking someone’s level of consciousness follows a simple progression: you start by seeing if they respond to your voice, then try physical stimulation if they don’t. Two widely used frameworks, the AVPU scale and the Glasgow Coma Scale, give you a structured way to assess and communicate how aware a person is. Whether you’re a first responder, a nursing student, or someone worried about a family member, understanding these tools helps you recognize how serious a situation is and describe it clearly to medical professionals.
Start With the AVPU Scale
The fastest way to gauge consciousness is the AVPU scale, which sorts a person into one of four categories:
- Alert: The person is aware of you and their surroundings without any prompting. They can open their eyes on their own, follow objects with their gaze, and respond to simple commands.
- Verbal: The person doesn’t open their eyes on their own but does respond when you speak to them. They react in a meaningful way, not just with random sounds or movements.
- Pain: The person doesn’t respond to your voice at all. They only react when you apply a physical stimulus, and that reaction might be movement, moaning, or crying out.
- Unresponsive: No reaction to anything. Not to your voice, not to physical stimulation.
AVPU works well as a rapid first check because it takes only seconds and requires no equipment. If someone falls below “Alert,” that’s a sign of significantly altered consciousness that needs medical attention. If they fall to “Pain” or “Unresponsive,” the situation is urgent.
The Glasgow Coma Scale for a Detailed Assessment
The Glasgow Coma Scale (GCS) provides a more precise picture by scoring three separate types of response: eye opening, verbal response, and motor response. Each category gets a point value, and you add them together for a total score between 3 (no response at all) and 15 (fully alert and oriented).
Eye Opening (1 to 4 Points)
- 4: Eyes open spontaneously
- 3: Eyes open to sound (your voice)
- 2: Eyes open to pain (physical stimulus)
- 1: No eye opening
Verbal Response (1 to 5 Points)
- 5: Oriented, knows who they are, where they are, and the date
- 4: Confused, speaks in sentences but gets details wrong
- 3: Inappropriate words, random or disorganized speech
- 2: Incomprehensible sounds, groaning or mumbling with no recognizable words
- 1: No verbal response
Motor Response (1 to 6 Points)
- 6: Obeys commands (squeeze my fingers, wiggle your toes)
- 5: Localizes pain, reaches toward the source of a stimulus to push it away
- 4: Withdraws from pain, pulls the limb away but doesn’t reach toward the stimulus
- 3: Abnormal flexion (arms curl inward toward the body)
- 2: Abnormal extension (arms straighten and rotate inward)
- 1: No motor response
A GCS of 15 means the person is fully conscious. A score of 13 to 14 suggests mild impairment. Scores between 9 and 12 indicate moderate impairment, and a score of 8 or below is considered severe. The threshold of 8 is especially significant: major trauma guidelines from the American College of Surgeons treat a GCS of 8 or lower as the point where a person can no longer protect their own airway and needs immediate intervention.
How to Apply Physical Stimulation Safely
If someone doesn’t respond to your voice, you need to try a physical stimulus to see if they react. Before jumping to painful pressure, try something less intense first: speak loudly, gently shake a shoulder, or call their name. If that doesn’t work, there are three accepted ways to apply central painful stimulation (meaning stimulation that tests brain-level response, not just a spinal reflex).
Trapezius squeeze: Grab the flat muscle between the neck and shoulder using your thumb and two fingers, then twist firmly. Don’t use this if you suspect a broken collarbone.
Sternal pressure: Make a fist and press your knuckles into the center of the person’s chest. You may need to apply pressure for up to 30 seconds. Avoid this if the person has a chest injury, and don’t repeat it every hour because it can cause skin breakdown.
Supraorbital pressure: Run your thumb along the bony ridge under the eyebrow until you find a small notch, then press firmly into it. This produces intense localized pain similar to a sinus headache. Skip this method if there’s any chance of facial fractures.
Pinching and pressing on fingernails are not recommended. Nail pressure tests spinal reflexes rather than brain-level consciousness, which means it can give misleading results.
What Abnormal Posturing Tells You
When you apply a painful stimulus, watch carefully for how the body responds. Two specific patterns of involuntary movement signal serious brain injury and are scored on the GCS motor scale.
Decorticate posturing shows up as the arms bending inward, with the wrists and fingers flexing while the legs straighten and the feet point downward. This pattern indicates damage in the upper brain, above a structure in the midbrain called the red nucleus. It corresponds to a GCS motor score of 3.
Decerebrate posturing looks different: the arms straighten and rotate inward with the forearms turning palm-down, while the legs extend in the same way. This signals damage deeper in the brainstem, below the red nucleus, and carries a worse prognosis. It scores a 2 on the motor component. As brain compression worsens, a person’s posturing can progress from decorticate to decerebrate, so any change in this pattern over time is critical information for emergency teams.
Checking Pupils for Additional Clues
Pupil response adds another layer to a consciousness assessment. Shine a light into each eye and watch whether the pupil constricts. Healthy pupils shrink quickly and symmetrically. Fixed, dilated pupils (large and unresponsive to light) suggest dangerous pressure building inside the skull, often from a mass or swelling compressing the brain. In comatose patients, non-reactive dilated pupils are associated with poor outcomes.
Pinpoint pupils that don’t respond to light, especially paired with slowed breathing and unconsciousness, point toward opioid overdose. Recognizing this specific triad matters because opioid overdose is reversible with prompt treatment.
Assessing Consciousness in Infants and Young Children
The standard GCS verbal and motor criteria assume the person can speak and follow commands, so a modified version exists for children under two. Instead of checking for oriented speech, you evaluate whether a baby coos and babbles normally (the highest score), is irritable and crying, cries only in response to pain, moans in response to pain, or makes no sound at all. For motor response, the top score goes to spontaneous, purposeful movement rather than obeying commands, and “withdraws to touch” replaces “localizes pain.” Children older than two use criteria that closely match the adult scale, with minor wording adjustments.
The overall scoring and thresholds remain the same. A total of 15 still means fully responsive, and 8 or below still signals a critical situation.
Red Flags That Signal an Emergency
Any drop in consciousness deserves attention, but certain findings alongside altered awareness indicate immediate danger. Low blood sugar is one of the most common and most treatable causes of sudden altered consciousness. If you have access to a glucose meter, checking blood sugar should be one of the first things you do. Low oxygen levels are another reversible cause, so check whether the person is breathing adequately.
Look for signs of trauma by checking the head, neck, and body for bruising, bleeding, or deformity. If trauma is possible, keep the neck still. Check for drug patches on the skin, medical alert bracelets, or nearby medications that might explain the change. Feel the person’s skin temperature: extreme heat or cold can both alter consciousness. A rash of tiny reddish-purple dots (petechiae) can indicate a dangerous infection. Any combination of abnormal vital signs with impaired consciousness, such as very low blood pressure, a racing or irregular heartbeat, or labored breathing, should be treated as an emergency requiring immediate help.