What initial assessments should I perform for a patient presenting with reduced consciousness to determine the underlying cause?

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Posted: 22 August 2025Updated: 22 August 2025 Guideline-Aligned (High Confidence) Clinically Reviewed
Dr Kola Tytler MBBS CertHE MBA MRCGPClinical Lead • iatroX

When a patient presents with reduced consciousness, the initial assessments should prioritise stabilising airway, breathing, and circulation (ABC) to address the greatest threat to life first.

Assessment should include measuring the Glasgow Coma Scale (GCS) score, detailing the eye opening, verbal, and motor responses separately, and recording the total score out of 15 to quantify the level of consciousness.

For patients with a GCS score less than 15, immediate assessment by a trained healthcare professional is essential to determine the severity and underlying cause.

In cases where the GCS score is 8 or less, early involvement of clinicians trained in advanced airway management and resuscitation is required.

Clinical examination should be extended to identify any risk factors for traumatic brain injury or cervical spine injury, guiding the need for imaging such as CT scans.

Consideration should also be given to other causes of reduced consciousness beyond trauma, including intoxication, but only after excluding significant brain injury.

Documentation and communication of findings, including GCS components and any safeguarding concerns, are critical during assessment and transfer.

Educational content only. Always verify information and use clinical judgement.