Delirium is one of the most common and clinically significant neuropsychiatric syndromes encountered in hospitalized adults, particularly among older patients, critically ill individuals, and those undergoing major surgery. Characterized by an acute disturbance in attention, awareness, and cognition, delirium is associated with increased mortality, prolonged hospitalization, functional decline, institutionalization, long-term cognitive impairment, and substantial healthcare costs. Despite its prevalence, delirium remains underrecognized, especially in patients presenting with hypoactive symptoms.Advances in recent years have improved understanding of the complex pathophysiological mechanisms underlying delirium, highlighting the interplay between neuroinflammation, neurotransmitter imbalance, oxidative stress, blood-brain barrier dysfunction, and impaired cerebral network connectivity. Prevention through multicomponent, non-pharmacological interventions remains the most effective strategy for reducing delirium incidence, while pharmacological therapy continues to have a limited role and should be reserved for carefully selected patients with severe distress or behaviours that threaten patient or staff safety.Emerging research has focused on artificial intelligence (AI)-based prediction models, blood-based biomarkers, electroencephalography, and precision medicine approaches that may improve early identification of high-risk patients and facilitate individualized prevention strategies. However, important challenges remain, including the underrecognition of hypoactive delirium, limited evidence supporting pharmacological interventions, and the need for prospective validation of emerging diagnostic technologies.This narrative review summarizes the contemporary evidence regarding the epidemiology, pathophysiology, risk factors, diagnosis, prevention, and management of delirium in hospitalized adults while highlighting current controversies, recent advances, and future directions that may shape clinical practice.