Illusion

Definition

An illusion is a misinterpretation of a real external stimulus, for example, seeing a coat hanging on a door and thinking it is a person. It differs from a hallucination, which has no external stimulus.

Causes

• Sensory impairment (poor vision/hearing)
• Delirium
• Dementia
• Psychosis
• Fatigue, stress, strong emotion
• Substances (alcohol, hallucinogens)
• Poor lighting

Therapeutic Communication

Acknowledge the misperception, then gently clarify reality: 'I see what you mean, but that is actually your robe on the chair.' Correct sensory deficits (glasses, hearing aids), improve lighting, reduce stimuli (reorient frequently).

Nursing Considerations

Assess for underlying cause (ensure safety). Illusions in delirium may improve with treatment of underlying condition. Recurring visual illusions in an elderly patient may indicate delirium or Lewy body dementia.

NCLEX Relevance

Illusion: misinterpret real stimulus. Hallucination: no stimulus. Differentiate in psychiatric assessment.