Recent-Onset Altered Mental Status: Evaluation and Management


Am Fam Physician. 2021 Nov ;104(5):461-470.

Author disclosure: No relevant financial affiliations.

Potential precipitating factors for the recent onset of altered mental status (AMS) include primary central nervous system insults, systemic infections, metabolic disturbances, toxin exposure, medications, chronic systemic diseases, and psychiatric conditions. Delirium is also an important manifestation of AMS, especially in older people who are hospitalized. Clinicians should identify and treat reversible causes of the AMS, some of which require urgent intervention to minimize morbidity and mortality. A history and physical examination guide diagnostic testing. Laboratory testing, chest radiography, and electrocardiography help diagnose infections, metabolic disturbances, toxins, and systemic conditions. Neuroimaging with computed tomography or magnetic resonance imaging should be performed when the initial evaluation does not identify a cause or raises concern for intracranial pathology. Lumbar puncture and electroencephalography are also important diagnostic tests in the evaluation of AMS. Patients at increased risk of AMS benefit from preventive measures. The underlying etiology determines the definitive treatment. When intervention is needed to control patient behaviors that threaten themselves or others, nonpharmacologic interventions are preferred to medications. Physical restraints should rarely be used and only for the shortest time possible. Medications should be used only when nonpharmacologic treatments are ineffective.

Altered mental status (AMS) can present as changes in consciousness, appearance, behavior, mood, affect, motor activity, or cognitive function.13 Recent changes are the focus of this article and are approached differently than chronic changes. Recent changes occur within seconds to days and usually pose a more immediate threat to a patient's well-being than chronic changes.24

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Clinical recommendationEvidence ratingComments

Delirium is common but frequently overlooked, and it is associated with serious medical conditions; therefore, screening should always be considered in patients with acute AMS, especially in those at high risk.6,9,11


Systematic review, narrative review, and expert consensus

Unless the etiology is clear and the risk of intracranial pathology is low, neuroimaging should be part of the initial assessment of recent changes in mental status. Noncontrast computed tomography of the head is the initial study for most patients.1214


Expert consensus

Electroencephalography is an important study to rule out nonconvulsive seizures, which may occur in 8% to 30% of patients with AMS without an obvious cause.16


Evidence-based review

When patients are at risk of AMS or delirium, nonpharmacologic preventive measures decrease incidence, especially in those who are hospitalized. The use of multiple measures through a multidisciplinary team approach is most effective.6,9,11


Systematic review, narrative reviews, and expert consensus

Medication to manage behaviors associated with AMS should be used only when nonpharmacologic measures are ineffective, and then only when it is essential to control behavior. Studies evaluating the effectiveness of medications used for their sedative effects yield conflicting results, and these medications may cause harm due to adverse effects.11,23,24


Systematic reviews, cohort study, and expert consensus

AMS = altered mental status.

A = consistent, good-quality patient-oriented evidence; B = inconsistent or limited-quality patient-oriented evidence; C = consensus, disease-oriented evidence, usual practice, expert opinion, or case series. For information about the SORT evidence rating system, go to

The Authors

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BRIAN VEAUTHIER, MD, is the program director of the University of Wyoming Family Medicine Residency Program, Casper....

JAIME R. HORNECKER, PharmD, BCPS, BCACP, CDCES, DPLA, is a clinical professor at the University of Wyoming School of Pharmacy and the Family Medicine Residency Program.

TABITHA THRASHER, DO, is the program director of the University of Wyoming Geriatric Fellowship and a clinical assistant faculty member at the University of Wyoming Family Medicine Residency Program.

Author disclosure: No relevant financial affiliations.

Address correspondence to Brian Veauthier, MD, 1522 E. A St., Casper, WY 82601 (email: Reprints are not available from the authors.


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1. Norris D, Clark MS, Shipley S. The mental status examination. Am Fam Physician. 2016;94(8):635–641. Accessed July 14, 2021.

2. Smith AT, Han JH. Altered mental status in the emergency department. Semin Neurol. 2019;39(1):5–19.

3. Douglas VC, Josephson SA. Altered mental status. Continuum (Minneap Minn). 2011;17(5 Neurologic Consultation in the Hospital):967–983.

4. Erkkinen MG, Berkowitz AL. A clinical approach to diagnosing encephalopathy. Am J Med. 2019;132(10):1142–1147.

5. Kanich W, Brady WJ, Huff JS, et al. Altered mental status: evaluation and etiology in the ED. Am J Emerg Med. 2002;20(7):613–617.

6. Kalish VB, Gillham JE, Unwin BK. Delirium in older persons: evaluation and management [published corrections appear in Am Fam Physician. 2015;92(6):430, and Am Fam Physician. 2014;90(12):819]. Am Fam Physician. 2014;90(3):150–158. Accessed July 14, 2021.

7. Witlox J, Eurelings LSM, de Jonghe JFM, et al. Delirium in elderly patients and the risk of postdischarge mortality, institutionalization, and dementia: a meta-analysis. JAMA. 2010;304(4):443–451.

8. Kakuma R, du Fort GG, Arsenault L, et al. Delirium in older emergency department patients discharged home: effect on survival. J Am Geriatr Soc. 2003;51(4):443–450.

9. Mattison MLP. Delirium. Ann Intern Med. 2020;173(7):ITC49–ITC64.

10. Wilber ST, Ondrejka JE. Altered mental status and delirium. Emerg Med Clin North Am. 2016;34(3):649–665.

11. Oh ES, Fong TG, Hshieh TT, et al. Delirium in older persons: advances in diagnosis and treatment. JAMA. 2017;318(12):1161–1174.

12. Lowenstein DH, Martin JB, Hauser SL. Chapter 415: Approach to the patient with neurologic disease. In: Jameson JL, Kasper DL, Fauci AS, et al., eds. Harrison's Principles of Internal Medicine, 20e. McGraw-Hill; 2018.

13. Luttrull MD, Boulter DJ, Kirsch CFE, et al.; Expert Panel on Neurological Imaging. ACR Appropriateness Criteria acute mental status change, delirium, and new onset psychosis. J Am Coll Radiol. 2019;16(5S):S26–S37.

14. Salmela MB, Mortazavi S, Jagadeesan BD, et al.; Expert Panel on Neurologic Imaging. ACR Appropriateness Criteria cerebrovascular disease. J Am Coll Radiol. 2017;14(5S):S34–S61.

15. Lee RK, Burns J, Ajam AA, et al.; Expert Panel on Neurological Imaging. ACR Appropriateness Criteria seizures and epilepsy. J Am Coll Radiol. 2020;17(5S):S293–S304.

16. Zehtabchi S, Abdel Baki SG, Malhotra S, et al. Nonconvulsive seizures in patients presenting with altered mental status: an evidence-based review. Epilepsy Behav. 2011;22(2):139–143.

17. Hemphill J III, Smith S, Josephson S, et al. Severe acute encephalopathies and critical weakness. In: Jameson JL, Kasper DL, Fauci AS, et al., eds. Harrison's Principles of Internal Medicine, 20e. McGraw-Hill; 2018.

18. Young GB. Metabolic and inflammatory cerebral diseases: electrophysiological aspects. Can J Neurol Sci. 1998;25(1):S16–S20.

19. Fick DM, Inouye SK, Guess J, et al. Preliminary development of an ultrabrief two-item bedside test for delirium. J Hosp Med. 2015;10(10):645–650.

20. Shahan B, Choi EY, Nieves G. Cerebrospinal fluid analysis [published correction appears in Am Fam Physician. 2021;103(12):713]. Am Fam Physician. 2021;103(7):422–428. Accessed May 29, 2021.

21. Hasbun R, Abrahams J, Jekel J, et al. Computed tomography of the head before lumbar puncture in adults with suspected meningitis. N Engl J Med. 2001;345(24):1727–1733.

22. Stone ND, Ashraf MS, Calder J, et al.; Society for Healthcare Epidemiology Long-Term Care Special Interest Group. Surveillance definitions of infections in long-term care facilities: revisiting the McGeer criteria. Infect Control Hosp Epidemiol. 2012;33(10):965–977.

23. Herzig SJ, LaSalvia MT, Naidus E, et al. Antipsychotics and the risk of aspiration pneumonia in individuals hospitalized for nonpsychiatric conditions: a cohort study. J Am Geriatr Soc. 2017;65(12):2580–2586.

24. Nikooie R, Neufeld KJ, Oh ES, et al. Antipsychotics for treating delirium in hospitalized adults: a systematic review. Ann Intern Med. 2019;171(7):485–495.



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