 Introduction/Background Altered mental status (AMS) and coma are terms used to describe disorders of arousal and content of consciousness. AMS may account for up to 4% to 10% of chief complaints in the emergency department (ED) setting and is a common accompanying symptom for other presentations [1,2]. AMS is not a diagnosis but rather a term for symptoms of acute or chronic disordered mentation [1], including confusion, disorientation, lethargy, drowsiness, somnolence, unresponsiveness, agitation, altered behavior, inattention, hallucinations, delusions, and psychosis [3,4]. Some of the most common disorders associated with AMS are underlying medical conditions, substance use, and mental disorders [5]. Validated assessment scales, such as the Richmond Agitation Sedation Scale and Glasgow Coma Scale, may be employed to objectively quantify the severity of symptoms [3,4]. The cause of AMS in patients across all age groups remains undiagnosed in slightly >5% of cases. Overall mortality in patients with AMS is approximately 8.1% and is significantly higher in elderly patients [4]. Two studies found that older patients presenting to the ED with the nonspecific chief complaint of AMS are likely to have delirium [6]. Delirium is a defined and diagnosable medical condition under Diagnostic and Statistical Manual of Mental Disorders, Fifth edition, which includes inattention as a cardinal feature, may fluctuate over the course of day with lucid intervals, and may present with subtle disturbances in consciousness compared with other forms of acute AMS, making detection more difficult and thus easy to miss [3,6]. Delirium is considered a medical emergency. Early detection and accurate diagnosis are extremely important because mortality in patients may be twice as high if the diagnosis of delirium is missed [7].
Altered Mental Status Coma Delirium and Psychosis.  Introduction/Background Altered mental status (AMS) and coma are terms used to describe disorders of arousal and content of consciousness. AMS may account for up to 4% to 10% of chief complaints in the emergency department (ED) setting and is a common accompanying symptom for other presentations [1,2]. AMS is not a diagnosis but rather a term for symptoms of acute or chronic disordered mentation [1], including confusion, disorientation, lethargy, drowsiness, somnolence, unresponsiveness, agitation, altered behavior, inattention, hallucinations, delusions, and psychosis [3,4]. Some of the most common disorders associated with AMS are underlying medical conditions, substance use, and mental disorders [5]. Validated assessment scales, such as the Richmond Agitation Sedation Scale and Glasgow Coma Scale, may be employed to objectively quantify the severity of symptoms [3,4]. The cause of AMS in patients across all age groups remains undiagnosed in slightly >5% of cases. Overall mortality in patients with AMS is approximately 8.1% and is significantly higher in elderly patients [4]. Two studies found that older patients presenting to the ED with the nonspecific chief complaint of AMS are likely to have delirium [6]. Delirium is a defined and diagnosable medical condition under Diagnostic and Statistical Manual of Mental Disorders, Fifth edition, which includes inattention as a cardinal feature, may fluctuate over the course of day with lucid intervals, and may present with subtle disturbances in consciousness compared with other forms of acute AMS, making detection more difficult and thus easy to miss [3,6]. Delirium is considered a medical emergency. Early detection and accurate diagnosis are extremely important because mortality in patients may be twice as high if the diagnosis of delirium is missed [7].