Confusion refers to a disturbance in mental clarity and orientation, affecting a patient’s ability to think quickly, reason clearly, and respond appropriately to environmental stimuli. It is a nonspecific but critical sign that may indicate an underlying acute or chronic pathology. Confusion may develop abruptly or gradually and can be transient, fluctuating, or permanent. It is especially common in hospitalized patients, particularly the elderly, where it is frequently misattributed to irreversible cognitive decline (e.g., dementia).

Delirium vs Dementia

Confusion is often categorized into acute (delirium) and chronic (dementia) forms:

• Delirium is characterized by sudden-onset confusion, inattention, disorganized thinking, and fluctuating levels of consciousness, often with hallucinations or psychomotor disturbances. It is typically reversible and requires urgent evaluation.

• Dementia is a progressive, chronic disorder marked by irreversible cognitive decline involving memory, executive function, and judgment. It usually develops insidiously over months to years.

Clinical assessment

History

A thorough clinical history is crucial. Because patients may be unable to describe their confusion, collateral information from caregivers is essential. Key questions include:

• Onset and duration (acute vs. chronic)

• Fluctuations in symptoms

• Precipitating events (e.g., infection, trauma, medication change)

• Past medical history (e.g., cardiovascular, metabolic, or neurologic conditions)

• Medication history including over-the-counter and herbal supplements

• Substance use (alcohol, recreational drugs)

Associated symptoms

• Hallucinations, disorientation

• Memory loss

• Language difficulties

• Sleep disturbances

• Behavior changes

Physical examination

• Vital signs: Identify fever, hypotension, bradycardia, tachycardia, or hypoxia

• Neurologic exam: Assess for focal deficits, altered level of consciousness, reflexes

• General exam: Look for signs of dehydration, infection, trauma, or systemic illness

Cognitive assessment tools

• Confusion Assessment Method (CAM)

• Mini-Mental State Examination (MMSE)

• Montreal Cognitive Assessment (MoCA)

• Glasgow Coma Scale (GCS) for consciousness level

Etiologies of confusion

Table: Medical and Other Causes of Confusion with Distinguishing Features

Toxic and drug-induced causes

Special Populations

Elderly Patients

• Prone to delirium from minor stressors (UTIs, constipation, medication changes).

• Often misdiagnosed due to baseline cognitive impairment or poor communication.

Pediatrics

• Confusion may be subtle and present as irritability or behavioral changes.

• Acute febrile illnesses may cause transient delirium.

• Metabolic errors, trauma, or meningitis should be promptly ruled out.

Management principles

Immediate priorities

• Ensure airway, breathing, and circulation (ABCs)

• Correct hypoxia, hypoglycemia, or electrolyte imbalances promptly

• Discontinue offending medications or substances

• Treat underlying infections or systemic causes

Supportive measures

• Reorient patient regularly with clocks, calendars, and familiar faces

• Avoid restraints unless absolutely necessary

• Promote sleep hygiene and reduce nighttime disturbances

• Hydration and nutritional support

• Monitor for complications: falls, aspiration, pressure injuries

Patient and family counseling

• Explain the nature of confusion and its underlying cause

• Provide reassurance about reversibility when appropriate

• Engage family in reorientation and communication strategies

• Encourage adherence to medication and follow-up plans

Conclusion

Confusion is a multifaceted clinical sign with a broad differential diagnosis. Effective evaluation involves a thorough history, targeted physical and neurologic examination, and appropriate investigations. Prompt identification and correction of reversible causes, especially in vulnerable populations such as the elderly or critically ill, can lead to significant improvements in outcome.

References

1. Inouye SK, Westendorp RG, Saczynski JS. Delirium in elderly people. Lancet. 2014;383(9920):911-22.

2. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 5th ed. Arlington: APA; 2013.

3. Trzepacz PT, Meagher DJ. Delirium: A Clinical and Scientific Overview. Oxford: Oxford University Press; 2018.

4. Ropper AH, Samuels MA, Klein JP. Adams and Victor’s Principles of Neurology. 11th ed. New York: McGraw-Hill; 2019.

5. Fong TG, Tulebaev SR, Inouye SK. Delirium in elderly adults: diagnosis, prevention and treatment. Nat Rev Neurol. 2009 Apr;5(4):210-20.

6. Lipowski ZJ. Delirium: acute confusional states. Oxford: Oxford University Press; 1990.

7. Han JH, Wilson A, Vasilevskis EE, et al. Delirium in the emergency department: an independent predictor of death within six months. Ann Emerg Med. 2010;56(3):244-52.

8. O’Hanlon S, O’Regan N, MacLullich AM. The diagnosis and management of delirium in the acute hospital. Age Ageing. 2014;43(5):496–502.