“She’s always confused.”
The care aide says it with a shrug as you assess your 84-year-old patient. She is disoriented to time and place, picking at her blankets, and does not seem to recognize her room. The chart says dementia.
Case closed?
Not so fast. Because this confusion might be something very different—and very fixable—if you catch it.
Delirium vs. Dementia: Why It Matters
Dementia is a chronic, slowly progressive decline in cognitive function. It is their baseline. It is sad, but it is not an emergency.
Delirium is an acute change in mental status caused by something else—infection, medication, metabolic problem, hypoxia. It is a symptom, not a diagnosis. And that “something else” can kill them if you miss it.
The danger: when we hear “dementia,” we sometimes stop looking. But a delirious patient needs you to find the cause.
The 5-Minute Field Assessment
You do not need a formal cognitive test. You need the right questions:
Ask the caregiver:
- “Is this her normal, or is this different?”
- “When did you last see her acting completely like herself?”
- “Did this come on suddenly or gradually?”
- “Any new medications in the past week?”
- “Eating and drinking normally? Any vomiting or diarrhea?”
- “Fever, cough, urinary symptoms?”
- “Any falls recently, even minor ones?”
The key distinction:
- Dementia: Gradual onset, stable day-to-day, worse in evenings (sundowning), memory primarily affected
- Delirium: Acute onset (hours to days), fluctuating, affects attention and awareness, often has a cause
Common Causes of Delirium in the Elderly
Think of these when you see acute confusion:
- Infection — UTI is famous for this, but pneumonia and skin infections too
- Medications — New meds, changed doses, or missed doses (especially psych meds)
- Metabolic — Hypoglycemia, hyponatremia, dehydration, renal failure
- Hypoxia — Check that SpO2
- Urinary retention — A full bladder can absolutely cause delirium
- Constipation/impaction — Surprisingly common cause
- Pain — Undertreated pain, especially from fractures
- Head injury — Even “minor” falls in anticoagulated patients
- Stroke/TIA — Confusion can be the only presenting symptom
What “Sundowning” Is (and Is Not)
Sundowning—increased confusion in the evening—is a real phenomenon in dementia patients. But it has become a catch-all excuse for any confused elderly person after dark.
Be careful: “It’s just sundowning” can mask a UTI, a stroke, or a medication error. If the family says this is worse than their usual sundowning, believe them.
Your Assessment Findings That Suggest Delirium
- Acute onset (hours to days, not months)
- Fluctuating level of consciousness
- Cannot focus attention on your questions
- Vital sign abnormalities (fever, tachycardia, hypoxia)
- Visual hallucinations (more common in delirium than dementia)
- Hyperactive (agitated) or hypoactive (withdrawn, “quiet”)
The Pearl
“They’re always confused” does not mean THIS confusion is not an emergency. Ask when they were last normal. If this is different from baseline—especially if it came on acutely—there is a cause, and finding it could save their life.
This clinical pearl is for educational discussion only. Assessment and transport decisions should follow your local protocols and medical direction. When in doubt about an elderly patient’s mental status change, err on the side of further evaluation.