The key to the treatment of unconsciousness is an understanding of the underlying pathophysiology. Management of the unconscious patient should be targeted towards the diagnosis and treatment of the cause combined with supportive care of the patient, while the ultimate cause is elucidated. The basic tenants of emergency and critical care medicine—the ABC’s—apply to the unconscious patient with particular care if occult cervical spine injury is a possibility. The prognosis of disorders of consciousness depends heavily on the aetiology and accurate prognostication can be difficult even when the underlying cause has been determined.