Delirium is a common, serious, and often fatal condition in elderly patients, characterized by acute cognitive and attentional impairment. It is frequently under-recognized and poorly understood, despite being a major public health issue. Delirium is a multifactorial condition, and nonpharmacologic interventions are the most effective for prevention. Pharmacologic treatments lack convincing evidence of effectiveness. Delirium serves as a marker of brain vulnerability and may lead to permanent cognitive damage. It is a critical patient safety indicator and a target for healthcare quality improvement. Delirium diagnosis requires a formal cognitive assessment and acute symptom onset. It is often overlooked, but early recognition is crucial for effective management. Delirium is associated with increased mortality, cognitive decline, and institutionalization in elderly patients. It is more common in intensive care, postoperative, and palliative care settings. Delirium is linked to adverse outcomes in various patient populations, including those with dementia. Delirium is a clinical diagnosis, often missed due to its fluctuating nature. Diagnostic tools such as the Confusion Assessment Method (CAM) are widely used. Delirium has two main forms: hypoactive and hyperactive. Hypoactive delirium is more common in older patients and is associated with worse outcomes. Delirium is often linked to underlying medical conditions and can be exacerbated by stressors such as infections. Delirium management focuses on nonpharmacologic approaches, including reducing psychoactive medications, promoting sleep, and ensuring patient safety. Pharmacologic treatments are reserved for severe cases. Nonpharmacologic interventions, such as the Hospital Elder Life Program (HELP), have shown effectiveness in preventing delirium and functional decline. These programs include reorientation, therapeutic activities, and reducing psychoactive medications. Pharmacologic treatments for delirium lack strong evidence of effectiveness and may worsen outcomes. Current research highlights the need for further investigation into delirium's pathophysiology and its role in cognitive decline and dementia. Delirium is a complex condition with significant implications for healthcare quality and patient outcomes. Future research should focus on improving delirium recognition, prevention, and management strategies to enhance patient care and reduce healthcare costs.Delirium is a common, serious, and often fatal condition in elderly patients, characterized by acute cognitive and attentional impairment. It is frequently under-recognized and poorly understood, despite being a major public health issue. Delirium is a multifactorial condition, and nonpharmacologic interventions are the most effective for prevention. Pharmacologic treatments lack convincing evidence of effectiveness. Delirium serves as a marker of brain vulnerability and may lead to permanent cognitive damage. It is a critical patient safety indicator and a target for healthcare quality improvement. Delirium diagnosis requires a formal cognitive assessment and acute symptom onset. It is often overlooked, but early recognition is crucial for effective management. Delirium is associated with increased mortality, cognitive decline, and institutionalization in elderly patients. It is more common in intensive care, postoperative, and palliative care settings. Delirium is linked to adverse outcomes in various patient populations, including those with dementia. Delirium is a clinical diagnosis, often missed due to its fluctuating nature. Diagnostic tools such as the Confusion Assessment Method (CAM) are widely used. Delirium has two main forms: hypoactive and hyperactive. Hypoactive delirium is more common in older patients and is associated with worse outcomes. Delirium is often linked to underlying medical conditions and can be exacerbated by stressors such as infections. Delirium management focuses on nonpharmacologic approaches, including reducing psychoactive medications, promoting sleep, and ensuring patient safety. Pharmacologic treatments are reserved for severe cases. Nonpharmacologic interventions, such as the Hospital Elder Life Program (HELP), have shown effectiveness in preventing delirium and functional decline. These programs include reorientation, therapeutic activities, and reducing psychoactive medications. Pharmacologic treatments for delirium lack strong evidence of effectiveness and may worsen outcomes. Current research highlights the need for further investigation into delirium's pathophysiology and its role in cognitive decline and dementia. Delirium is a complex condition with significant implications for healthcare quality and patient outcomes. Future research should focus on improving delirium recognition, prevention, and management strategies to enhance patient care and reduce healthcare costs.