The Unconscious Patient: A Case-Based Approach

The case: found less responsive than usual

In our teaching scenario, a man in his sixties is found by his wife slumped in a chair, breathing but very difficult to wake. He mumbles when shaken but does not open his eyes or speak clearly. She cannot get any sense from him and rightly calls 999. When paramedics arrive, their first job is not to guess the cause but to keep him safe and gather clues. Reduced consciousness ranges from mild drowsiness to deep coma, and the level can change quickly. The key early questions are simple: is he breathing safely, and how deeply is his consciousness affected? Everything else follows from protecting life first.

The ABCDE approach and protecting the airway

NHS emergency teams assess every seriously ill person using a structured airway, breathing, circulation, disability and exposure approach, always in that order. For an unconscious person, the airway comes first, because someone who cannot protect their own airway may choke on saliva or vomit, or their tongue may fall back and block breathing. Simple actions, such as tilting the head, lifting the chin, or turning them into the recovery position, can be lifesaving. Only once breathing and circulation are secured do the team turn to working out the cause. This order is deliberate: a perfect diagnosis is useless if the person stops breathing while it is being made.

Measuring consciousness: AVPU and GCS

To describe how awake someone is, staff use standard scales so everyone means the same thing. The quick AVPU scale asks whether a person is Alert, responds to Voice, responds to Pain, or is Unresponsive. The more detailed Glasgow Coma Scale, or GCS, scores eye opening, verbal response and movement, adding up to a number between three and fifteen. A falling score signals worsening and prompts urgent action. In our case, the man responds only to a firm voice and does not open his eyes, placing him low on both scales. Repeating the score over time shows the direction of travel, which matters as much as any single reading.

Searching for the cause

Many things can reduce consciousness, and doctors run through a mental checklist to avoid missing a treatable cause. Common culprits include low blood sugar, lack of oxygen, stroke or bleeding in the brain, infection, epileptic seizures, poisoning or overdose, and problems with salts, the kidneys or liver. The team checks blood sugar at the bedside within moments, because low sugar is common, dangerous and quickly reversible. They also look at the pupils, temperature, breathing pattern and any signs of injury, and ask relatives about medicines, alcohol, diabetes and recent illness. In our case, a very low blood sugar reading points to the likely cause and guides immediate, targeted treatment.

Treatment, monitoring and recovery

Once a probable cause is found, treatment is aimed at it while the person is watched closely. For our patient, correcting the low blood sugar leads to a rapid improvement in his level of consciousness, and further tests explore why it happened, perhaps a diabetes medicine and a missed meal. Throughout, staff keep monitoring his breathing, oxygen, blood pressure and GCS, ready to escalate to critical care if he does not improve. Recovery depends entirely on the underlying cause; some are quickly reversible, others need longer treatment. The general lesson is that reduced consciousness is always an emergency until proven otherwise, and it deserves a fast, structured and unhurried response.