• Delirium: Has a sudden and rapid onset (hours to days). It develops quickly, often in response to an underlying medical condition or environmental trigger.
• Dementia: Has a gradual and slow onset (months to years). It progresses slowly over time, often without a clear starting point.
Delirium: Usually short-term and temporary if the underlying cause is treated. Symptoms fluctuate throughout the day, and delirium can resolve within days or weeks if addressed.
• Dementia: Chronic and long-term. Dementia is generally irreversible and worsens over time, although some symptoms may be managed to slow progression.
Delirium: Symptoms typically fluctuate, with periods of lucidity followed by confusion or disorientation. The severity of symptoms often varies during the day, with worse symptoms at night (a phenomenon known as "sun downing").
• Dementia: The progression is steady and continuous, and cognitive decline is more stable over time, although some patients may experience worse symptoms later in the day (also sun downing).
Delirium: Attention is severely impaired. Patients may find it difficult to focus, shift, or maintain attention. They are often easily distracted.
• Dementia: Attention is typically better preserved, especially in the early stages. However, as dementia progresses, concentration may also become affected, though it's usually less acute than in delirium.
Delirium: The person often has altered levels of consciousness. They may swing between hyper-alert and drowsy states, or even seem less responsive at times.
• Dementia: Consciousness is generally clear. The individual remains alert and aware, although their memory and thinking abilities decline over time.
Delirium: In addition to attention deficits, patients with delirium experience disorganized thinking, confusion, memory problems, and perceptual disturbances (hallucinations or illusions). The cognitive impairment is usually temporary and related to the underlying medical cause.
• Dementia: Dementia is primarily marked by progressive memory loss, language problems, impaired judgment, and executive dysfunction. Hallucinations are less common in early dementia, though they can occur in later stages, especially in conditions like Lewy body dementia.
Delirium: Often reversible if the underlying cause (e.g., infection, medication, and dehydration) is treated promptly. Once the medical condition is resolved, cognitive function usually returns to normal.
• Dementia: Irreversible in most cases. Conditions like Alzheimer's disease, vascular dementia, or Lewy body dementia are degenerative, although certain symptoms may be managed or slowed with medication and lifestyle interventions.
Delirium: Usually caused by acute medical conditions or triggers, such as infections (e.g., UTIs, pneumonia), medications (e.g., sedatives, opioids), metabolic imbalances (e.g., dehydration, electrolyte disturbances), or substance withdrawal.
• Dementia: Typically results from chronic neurodegenerative diseases like Alzheimer's disease, vascular dementia, or frontotemporal dementia. It is linked to progressive brain damage or cell death over time.
Delirium: Treatment focuses on identifying and addressing the underlying cause (e.g., treating an infection, stopping a medication). With proper treatment, delirium often resolves.
• Dementia: There is no cure for most forms of dementia. Treatment focuses on symptom management (e.g., memory aids, medications to slow progression) and improving quality of life.
Delirium: Can occur at any age, though it is more common in older adults, especially those who are hospitalized, in ICU settings, or have underlying cognitive issues.
• Dementia: Primarily affects older adults, typically developing in individuals over 65, though early-onset dementia can appear in younger individuals.
