Situation: A 76-year-old retired teacher is brought to the medical ward by her daughter because of 2 days of confusion. Before this she lived independently and managed her own money. The nurse assesses her cognition as part of the mental status examination (MSE). Her daughter confirms the change began suddenly 2 days ago; before that, her memory and thinking were normal. Her alertness varies over the day: she is drowsy in the morning and restless and agitated at night. Which NANDA International (NANDA-I) 2024–2026 label BEST fits these data?

Acute confusion is an abrupt, reversible disturbance of consciousness, attention, and cognition that develops over a short time and fluctuates. Sudden onset 2 days ago, normal function before, and alertness that varies through the day fit this label rather than chronic confusion, which develops over a long period.

Clinical situation
A 76-year-old woman presents with a 2-day history of confusion. The key features are acute onset, fluctuating alertness (drowsy in the morning, restless and agitated at night), and a clear premorbid baseline of independent living and intact cognition. These data point to a disturbance of consciousness and attention rather than a pure memory deficit.

Why this is Acute confusion
The defining characteristics of acute confusion are abrupt onset, a fluctuating course, and impaired attention or awareness. Delirium—the clinical syndrome underlying this NANDA-I label—is described as a sudden-onset change in mental status with a fluctuating course, characterized chiefly by inattention or altered arousal ^[3][4]. The patient’s symptoms began only 2 days ago, and her daughter confirms normal cognition before that. This temporal profile is the strongest discriminator.

Key point! Acute confusion develops over hours to days, whereas chronic confusion evolves over weeks to months and reflects a more persistent cognitive decline. The sudden change from a normal baseline rules out chronic confusion.

The fluctuation in alertness—drowsy during the day and agitated at night—is a hallmark of delirium. A disturbance of consciousness that varies over the course of the day is not typical of dementia or isolated memory impairment. Delirium affects attention, awareness, and cognition acutely, and its presentation can shift between hyperactive, hypoactive, and mixed psychomotor profiles ^[3][4]. The patient’s daytime drowsiness and nighttime agitation suggest a mixed or fluctuating profile.

Why the other labels do not fit

NANDA-I label	Why it is less appropriate
Chronic confusion	Develops over a long period; irreversible or slowly progressive; not consistent with a 2-day change from normal baseline.
Impaired memory	Focuses on memory deficit alone; does not capture the altered consciousness, inattention, and fluctuating alertness seen here.
Risk for acute confusion	A risk label is used when the problem has not yet occurred; this patient already shows active signs of acute confusion.

Clinical significance for nursing assessment
Delirium in hospitalized older adults is common and carries serious consequences, including prolonged hospitalization, functional decline, long-term cognitive impairment, and increased mortality . Early identification is essential because delirium is often reversible when the underlying cause—such as infection, medication change, metabolic disturbance, or environmental stressor—is found and treated ^[3]. In the emergency department or medical ward, a sudden change in mental status should prompt immediate screening for delirium rather than being attributed to aging or dementia.

Watch out! Delirium is frequently missed, especially the hypoactive form where the patient is quiet and drowsy. A patient who is “just sleepy” during the day but agitated at night may still be delirious. The fluctuating course is a diagnostic clue, not a reason to delay assessment.

The NANDA-I label Acute confusion best captures the combination of abrupt onset, fluctuating consciousness, and inattention in a patient with a previously normal cognitive baseline. This label directs the nurse to search for reversible causes and to implement safety measures, reorientation strategies, and frequent monitoring of mental status.