Confusion

Acute confusion — a change in awareness, attention and coherent thinking over hours to days — is delirium until proven otherwise, and delirium is a medical emergency. It differs from dementia in tempo and attention: dementia develops over months to years with preserved alertness early on, while delirium fluctuates through the day and impairs the ability to sustain attention. Hypoactive delirium, where someone becomes quiet and withdrawn rather than agitated, is the more common form and the more frequently missed. The causes are almost always outside the brain. Urinary and chest infections, dehydration, constipation, urinary retention, uncontrolled pain, hypoxia, low sodium, low glucose and — very commonly — medication are the usual culprits. Anticholinergic drugs, opioids, benzodiazepines, sedating antihistamines and sudden alcohol withdrawal all feature heavily. Delirium is associated with longer hospital stays, higher mortality and accelerated cognitive decline afterwards, so early identification changes outcomes. Nutritional causes exist but are a minority: thiamine deficiency in alcohol use disorder causes Wernicke encephalopathy and is a genuine emergency treated with high-dose parenteral thiamine, and severe B12 deficiency can produce cognitive change. Neither is treated with over-the-counter supplements. There is no supplement that safely addresses new confusion, and self-treating delays the diagnosis that matters.

• •Reduced ability to sustain attention or follow conversation
• •Symptoms that fluctuate through the day and worsen at night
• •Disorientation to time or place
• •New hallucinations or paranoid ideas
• •Withdrawn, drowsy behaviour (hypoactive delirium)
• •Reversed sleep-wake cycle

• •Urinary or respiratory tract infection
• •Medication effects, especially anticholinergics, opioids and sedatives
• •Dehydration and electrolyte disturbance including low sodium
• •Hypoxia from any cause
• •Hypoglycaemia
• •Constipation or urinary retention
• •Alcohol or benzodiazepine withdrawal
• •Thiamine deficiency (Wernicke encephalopathy)
• •Stroke, head injury or seizure

Delirium reflects diffuse cortical dysfunction from a systemic insult — inflammatory cytokines, hypoperfusion, hypoxia, metabolic derangement or neurotransmitter disturbance, particularly cholinergic deficiency and dopaminergic excess. Vulnerability rises sharply with age, pre-existing cognitive impairment, sensory deficit and polypharmacy.