Altered Mental Status

by Murat Cetin, Begum Oktem, Mustafa Emin Canakci 

Case Presentation

An 80-year-old female presents to the emergency department with a tendency to sleep (altered mental status), failure in recognizing people and answering questions. She is a nursing-home inhabitant. The caregivers express she was feverish and fatigued for several days now, but her mental problems have recently begun. The patient has a history of hypertension and diabetes mellitus. Her only routine medications are angiotensin-converting enzyme inhibitors (ACE inhibitors) and insulins. Vital Signs: Blood Pressure: 110/70 mmHg, Heart rate: 110 bpm, respiratory rate: 20 rpm, temperature: 38.8 degrees Celsius, peripheral capillary oxygen saturation: 98%, finger-stick blood sugar: 95 mg/dL. Physical Exam: She is in mild distress, lethargic and confusional with no lateralizing signs. The pupils are reactive to light and equal in size. On a Glasgow Coma Scale, she is registered at 12 (E3, M5, V4) and she had neck stiffness. The heart is irregularly tachycardic with no abnormal cardiac sounds. The breath sounds are clear and equal bilaterally. The abdomen is soft, non-tender, non-distended. Skin: warm, dry, no rash. A lumbar puncture is performed to diagnose or exclude meningitis.

General Approach and Critical Bedside Actions

General Approach and Key Concepts

The state of consciousness is a sum of arousal and cognition. Arousal refers to awareness of the self and the environment. The Ascending Reticular Activating System in the brainstem modulates arousal. The Cognition is the combination of orientation, reasoning, and memory. The cerebral cortex houses the cognition centers. In sum, the normal state of consciousness requires a properly functioning brain stem and cerebral cortex.

Altered mental status may result from any changes in;

  • Arousal,
  • Cognition,
  • A combination of these two functions.

The altered mental state may mean coma, confusion, aggression, personality alteration, or difficulty in awakening. Approximately 3% of patients in the emergency department have impaired mental status. In the elderly patients, this rate is between 10% and 25%. 85% of patients have metabolic and systemic diseases.

Dementia and delirium should be differentiated in patients with altered mental status. Metabolic, infectious and vascular pathologies should be evaluated.

Delirium, Dementia and Psychiatric Patients

Delirium, Dementia and Psychiatric Patients

OnsetCourseLevel of ConsciousnessLevel of AttentionLevel of CognitionLevel of OrientationHallucinationsDelusionsExtra Movements
DeliriumGradualVaryingDecreasedConfusedConfusedImpairedYes, auditory or visualTransient, poorly organisedAsterixis, sometimes tremor
DementiaInsidiousSteadyAlertNormalImpairedUsually impairedUsually no hallucinationsUsually no delusionsNone
PsychiatricAbrupt onsetSteadyAlertMay be confusedMay be confusedMay be confusedAuditorySustainedNone
Differentiating Delirium, Dementia and Psychiatric patients is important. Please read Altered Mental Status and Coma chapter in Tintinalli, J. E., Stapczynski, J. S., Ma, O. J., Cline, D., Meckler, G. D., & Yealy, D. M. (Eds.). (2016). Tintinalli's emergency medicine: a comprehensive study guide (8th ed.). New York: McGraw-Hill Education.

Critical Bedside Actions

The initial evaluation must start with the evaluation of airway, breathing, and circulation (ABC) sequence. Life-threatening situations require rapid intervention. During the initial assessment, the reversible causes must be addressed and managed such as hypoglycemia or opioid overdose. A continuous cardiac monitoring and vascular access must be established as soon as possible.

  • A (Airway): Hypoxia is a reversible cause of altered mental status. Ensure the airway is open and protected. If not, secure the airway and give oxygen if necessary. We prefer oxygen saturation maintained above 94%.
  • B (Breathing): Inadequate ventilation may cause hypercarbia. If the respirations are inadequate or superficial, perform bag-mask ventilation (BVM) or endotracheal intubation. The combination of altered mental status and respiratory depression may suggest narcotic/opioid overdose.
  • C (Circulation): Hypoperfusion may cause altered mental status due to decreased oxygen and glucose in the brain. Check the distal pulses, blood pressure, and cardiac rhythm. Capillary refill time, skin color and temperature may also help to understand possible shock situation. If the patient is hypotensive, administer IV fluids and investigate the cause.
  • D (Mini neurological evaluation): Assess Glasgow Coma Score (GCS) or AVPU quickly. Check if the pupils are equal and reactive to light. Administer benzodiazepines (lorazepam or diazepam, based on availability) in case of ongoing seizure activity. Cervical stabilization should be provided if trauma is suspected.
  • E (Exposure): The findings should be evaluated in terms of trauma, transdermal drug tapes, dialysis intervention area, sources of infection and petechiae.
  • Glucose level, ECG should be performed. Bedside ultrasound (eFAST or RUSH protocols) should be added to the investigation of patients with shock or trauma.
  • The level of hemodynamic stability of the patient sets the pace of the investigation. A systematic approach, starting with history taking and focused physical examination is key to reaching a diagnosis and consequently definitive management.

Differential Diagnoses

Metabolic, infectious, toxicological, endocrine, hypoxic conditions may cause altered mental status. The mnemonic “AEIOU-TIPS” may help to remember most common causes of altered mental status.

Mnemonic AEIOU-TIPS for Altered Mental Status

Mnemonic “AEIOU-TIPS” for Altered Mental Status

AlcoholAlcohol levels, serum osmoles
Epilepsy/ Endocrine/ Electrolytes/ Encephalopathy EEG, referral to neurology, TFTs, cortisol, chemistry panel, LFTs/NH3
Oxygen/ Opiates SatO2%, ABG, hypoxia makes agitation, hypercarbia makes somnolence
Look for needle marks
Things changing serum osmolarity affect mental status. Uremia, Sugar, Alcohol are common ones
Trauma/ TemperatureCT Head, C-Collar, CT C-Spine
InfectionCBC, BCx, UA, UCx, CXR, LP/CSF
Sepsis and CNS infections are more important. But, even simple fever may cause AMS in elderly and kids
Poisoning/ Psychosis Drug Levels (e.g. lithium, digoxin)
Shock/ Stroke/ SAH/ Space occupying lesion ECG, Troponin, CT Head, LP


History Taking and Physical Examination Hints

History Taking

Obtain patient’s medical history directly from the patient. Determine if the level of awareness is decreased. If the patient is unable to provide the necessary information:

  • Ask a family member, caregiver, or medical personnel
  • Check for medical alert identification
  • Ask for medical information sheet (i.e., on the refrigerator)
  • Ask surrounding environment (i.e., living quarters, alcohol bottles or drug paraphernalia).

If the normal state of the patient is unclear, all changes must be evaluated as if they are acute. Strokes, seizures, cardiac events, intoxication, psychiatric disorders cause sudden changes, whereas; infections, metabolic disturbances, or an expanding intracranial mass may cause gradual changes.

Altered mental status is a result, not a diagnosis. The diagnosis is based on clinical suspicion. The cause may be transient (seizure) or permanent (stroke), benign or life-threatening. If not treated timely and accurately, most causes may be mortal or cause neurologic sequelae. The systematic and structured approach makes diagnosing and management easier.

Physical Examination Hints

A focused and systematic physical examination aims at confirming the clinical impression formed by the history. It also aids exposing unexpected findings that may make the clinician reassess the differential diagnoses and approach. Repetitive examinations should be performed to track changes.

  • Vital signs should be evaluated very carefully in terms of hypotension, hidden shock, hypoxia, respiratory rate and pattern, and temperature.
  • Head: Signs of trauma, pupils’ size and reaction to light, cterus, pale conjunctiva
  • The fundoscopic exam may show hemorrhage, papilledema
  • Neck: Rigidity, bruits, thyroid enlargement
  • Heart and Lungs may show heart failure, pneumonia findings
  • Abdomen: Organomegaly, ascites
  • Extremities: peripheral cyanosis
  • Skin: Diaphoretic/dry, rash, petechiae, ecchymoses, splinter hemorrhages, needle tracks
  • Neurologic exam should be done in order of GCS, FOUR score (see below), pupil dimensions, neck stiffness, lateralizations .  In the secondary evaluation, the full neurological exam should be applied. The mental status exam should be the main part of neurological exam and repeated as needed.
Glasgow Coma Scale
Choose the best response of patient
4: Spontaneously
3: To verbal command
2: To pain
1: No response
5: Oriented and converses
4: Disoriented and converses
3: Inappropriate words; cries
2: Incomprehensible sounds
1: No response
6: Obeys command
5: Localizes pain
4: Flexion withdrawal
3: Flexion abnormal (decorticate)
2: Extension (decerebrate)
1: No response
Glasgow Coma Score (GCS) (Modified from Teasdale, G., & Jennett, B. (1974). Assessment of coma and impaired consciousness: a practical scale. The Lancet, 304(7872), 81-84.) - Please read this article to get more insight regarding GCS.


Full Outline of Un-Responsiveness (FOUR) Score

Full Outline of Un-Responsiveness (FOUR) Score

4: Eyelids open or opened, tracking, or blinking to command
3: Eyelids open but not tracking
2: Eyelids closed but open to the loud voice
1: Eyelids closed but open to pain
0: Eyelids remain closed with pain
4: Thumbs-up, fist, or peace sign
3: Localizing to pain
2: Flexion response to pain
1: Extension response to pain
0: No response to pain or generalized myoclonus status
4: Pupil and corneal reflexes present
3: One pupil wide and fixed
2: Pupil or corneal reflexes absent
1: Pupil and corneal reflexes absent
0: Absent pupil, corneal, and cough reflex
4: Not intubated, regular breathing pattern
3: Not intubated, Cheyne-Stokes breathing pattern
2: Not intubated, irregular breathing
1: Breaths above ventilator rate
0: Breaths at ventilator rate or apnea
Gujjar AR, Jacob PC, Nandhagopal R, Ganguly SS, Obaidy A, Al-Asmi AR. Full Outline of UnResponsiveness score and Glasgow Coma Scale in medical patients with altered sensorium: interrater reliability and relation to outcome. J Crit Care. 2013 Jun;28(3):316.e1-8. doi: 10.1016/j.jcrc.2012.06.009. Epub 2012 Aug 9. PubMed
PMID: 22884530. - Please read this article to get more insight about this score.


Emergency Diagnostic Tests and Interpretation

Differential diagnosis of altered mental status is broad, and diagnostic tests should be targeted to suspected underlying pathologies. Rather than a single specific algorithm, a ruling in and out approach should be followed.

Bedside tests

  • Rapid glucose: Quick and easy. Hypoglycemia is an emergent cause and can be ruled out with this simple test, just in seconds. Glucose level should be measured at the bedside to understand hypo/hyperglycemia problems including diabetic ketoacidosis and hyperosmolar hyperglycemic state.
  • ECG may help to understand arrhythmias and some toxic effects of drugs such as TCA overdose.
  • Bedside US such as eFAST for trauma patients and RUSH protocol for nontraumatic hypotensive patients can be valuable to understand the underlying causes. Some other US applications can be used for altered mental status cases such as optic nerve sheet diameter measurement to understand increased intracranial pressure.

Laboratory tests

Many laboratory tests can help the management of altered mental status cases. These tests and their possible findings were given below.

Arterial/venous blood gas investigation is necessary for many critically ill patients to understand acidosis/alkalosis, hypercarbia, hypoxemia, carboxy-hemoglobinemia, methemoglobinemia, lactate, and base excess situation. Complete blood count can be used to search for Anemia/Polycythemia in hyperviscosity related pathologies, Leukopenia/ Leukocytosis in Infection and sepsis, Thrombocythemia / Thrombocytosis in spontaneous intracranial hemorrhage. Renal function tests (RFT) for uremia suspicion caused by acute or chronic renal failure. RFT can also be necessary to understand patients’ baseline before to order contrast-enhanced imaging or use some drugs. Liver function tests are useful in the suspicion of hepatic failure, hepatic encephalopathy or biliary tract problems. Electrolytes are essential to evaluate altered mental status. There are many electrolyte abnormalities can change the level of consciousness such as hypo/hypernatremia, hypo/hyperkalemia, hypo/hypercalcemia. Urinalysis shows ketone bodies of diabetic ketoacidosis and provides information about urinary tract infection. Thyrotoxicosis and myxoedema coma are important endocrine-related causes of altered mental status. Therefore thyroid function tests can be valuable in some circumstances. Cardiac enzymes can be necessary because myocardial infarction may cause a low ejection fraction or trigger arrhythmias and patients may show altered mental status.

Also, when needed:

  • Drug screening for a suspected overdose
  • Levels of specific medications such as antiepileptics, antipsychotics, digoxin, warfarin
  • Ethanol level, levels of toxic alcohols
  • Cerebrospinal fluid (CSF) tests after a lumbar puncture (LP)
  • Cultures (Blood, urine, CSF, etc.)

Imaging modalities

  • Head CT: Non-contrast CT for ruling out hemorrhage, mass effect, edema.

What is your opinion about below CT Head image in a patient with altered mental status?

Case – Motor vehicle accident, head trauma, GCS 9

43.1 - Epidural with air

  • Head MRI: In selected patients (e.g., ischemic stroke, sinus venous thrombosis)

What is your opinion about below MRI images in a patient with altered mental status?

Case – 3 days history of fever, headache and gradual altered mental status

26.2 - pneumocaccal meningitis after surg 2 26.1 - pneumocaccal meningitis after surg 1

  • EEG: If there is a suspicion for seizure, non-convulsive status epilepticus, etc.
  • Chest radiogram: When indicated, for evaluating suspected cardiac and pulmonary conditions (e.g., pneumonia, pleural effusion)

What is your opinion about below chest x-ray in a patient with altered mental status?

Case – 60 yo female, 7 days gradual history of dyspnea, cough, sputum and fever. Today, altered mental status.

40 yo Female with respiratory distress

Emergency Treatment Options

Initial Stabilization

As we mentioned above, “ABC” is the first step in the evaluation. Life-threatening conditions detected during these steps must be immediately intervened. After initial stabilization, a detailed examination must be performed and the underlying cause(s) must be investigated. Treatment strategies vary according to the underlying condition.

  • If hypoglycemia is detected, dextrose (preferably D50W) should be administered intravenously.
  • In undifferentiated comatose patients, A “coma cocktail” can be given. Oxygen is also in this category. A mnemonic called DONT stands for dextrose, oxygen, naloxone, and thiamine. The application of coma cocktail was changed over time. Today, we have bedside gluco-stick tests. Therefore, application of glucose mainly depends on the bedside glucose results. Similarly, we are using portable saturation devices, depending on the SatO2 level measured on the bedside, oxygen application decisions may change. Therefore, these drugs may not be routine blindly anymore. In addition, it is better to emphasize that flumazenil (a benzodiazepine antidote) is not in the coma cocktail, and should not be used routinely also.
  • Empiric antibiotics must be initiated as soon as possible if sepsis or central nervous system infection is suspected. Diagnostic tests and procedures such as performing LP must not delay antibiotics administration.


  • Dextrose: For hypoglycemic patients, 50 mL D50W.
  • Thiamine: For Wernicke’s encephalopathy, 100 mg IV
  • Naloxone: As an antidote for opioid overdose, 0.4 mg IV, can be repeated up to a total dose of 10 mg according to some resources.
  • Glucocorticoids: When cerebral edema due to CNS mass lesions is detected in cranial CT
  • Fluid resuscitation for indicated situations (e.g. hypotension, dehydration, DKA)

Specific antidote should be given in intoxications. Choose appropriate empiric antibiotics for the suspected source of infection and possible microorganisms. Broad-spectrum antibiotics are an option.

Intravenous insulin infusion for diabetic ketoacidosis or hyperosmolar hyperglycemic syndrome. Electrolyte imbalances must be corrected using appropriate fluid replacements.


  • LP: Indicated if central nervous system infection or or subarachnoid bleeding (with negative CT scan)  is suspected.

Pediatric, Geriatric, Pregnant Patient, and Other Considerations

Advanced age is an independent risk factor for acutely altered mental status. Almost half of the patients presenting ED with altered mental status are elderly. Neurologic etiology is more common in the geriatric population and is the leading cause. Having multiple diseases and using multiple medications obscure the diagnostic process. When renal or hepatic functions are impaired, patients become more prone to drug intoxication without overdose. Moreover, drug interactions should be kept in mind, especially when a new medication is initiated.

In the pediatric population, symptoms and clinical findings may be very subtle and non-specific. Obtaining a detailed history, learning the child’s baseline and shifts from that baseline, and repeated physical examinations are essential.

Etiology of altered mental status in the pediatric population differs from the one in the adults. In a child with an altered mental status, the mnemonic “VITAMINS” is helpful:


V     Vascular (e.g., AV malformations, vasculitis)
I       Infection (e.g., sepsis, meningitis, encephalitis)
T     Toxins (e.g., drugs, environmental toxins)
A     Accident/abuse (e.g., trauma with a suspicious history)
M     Metabolic (e.g., glycemic abnormalities, electrolyte imbalance)
I       Intussusception
N     Neoplasm
S     Seizure


In pregnant patients, in addition to the etiologies mentioned above, eclampsia must be kept in mind. Eclampsia, which is life-threatening both for the patient and fetus, is usually seen in the third trimester but can be seen during postpartum period as well. All pregnant patients with seizures or altered mental state must be investigated for eclampsia. Other conditions with increased risk during pregnancy are cerebral venous thrombosis, ischemic and hemorrhagic strokes.

Disposition Decisions

The decision on discharging or admitting the patient depends on the underlying cause of mental status change and the clinical situation of the patient. The majority of the patients require admission, either to the ward or intensive care unit.

If the underlying cause is completely reversed and unlikely to re-occur, the patient reached his/her baseline mental status, vital signs are normal and stable, preparing a discharge plan may be considered.

References and Further Reading

  • Bassin, B. S., Cooke, J. L., & Barsan, W. G. (2013). Altered mental status and coma. In: Emergency Medicine: Clinical Essentials. 2nd ed. Philadelphia, PA: Elsevier Saunders.
  • Park, E., & Abraham, M. K. (2014). Altered mental status and endocrine diseases. Emergency Medicine Clinics, 32(2), 367-378.
  • Rummans, T. A., Evans, J. M., Krahn, L. E., & Fleming, K. C. Delirium in elderly patients: evaluation and management. In Mayo Clinic Proceedings (Vol. 70, No. 10, pp. 989-998). Elsevier.
  • Inouye, S. K. (2006). Delirium in older persons. New England Journal of Medicine, 354(11), 1157-1165.
  • Morrissey, T. (2008). Altered Mental Status. Retrieved June 15, 2018 from
  • Kanich, W., Brady, W. J., Huff, J. S., Perron, A. D., Holstege, C., Lindbeck, G., & Carter, C. T. (2002). Altered mental status: evaluation and etiology in the ED. The American journal of emergency medicine20(7), 613-617.
  • Murphy, B. A., Jagoda, A. S., Mickel, H. S., Yealy, D. M., Cantrill, S. V., Smith, E. E., … & Gallagher, E. J. (1999). Clinical policy for the initial approach to patients presenting with altered mental status. Annals of emergency medicine33(2), 251-281.
  • Han, J. H., & Wilber, S. T. (2013). Altered mental status in older patients in the emergency department. Clinics in geriatric medicine29(1), 101-136.
  • Xiao, H. Y., Wang, Y. X., Teng-da Xu, H. D. Z., Guo, S. B., Wang, Z., & Yu, X. Z. (2012). Evaluation and treatment of altered mental status patients in the emergency department: life in the fast lane. World journal of emergency medicine3(4), 270.
  • Kekec, Z., Senol, V., Koc, F., & Seydaoglu, G. (2008). Analysis of altered mental status in Turkey. International Journal of Neuroscience118(5), 609-617.
  • Leong, L. B., Jian, K. H. W., Vasu, A., & Seow, E. (2010). Identifying risk factors for an abnormal computed tomographic scan of the head among patients with altered mental status in the Emergency Department. European Journal of Emergency Medicine17(4), 219-223.
  • Horeczko, T. (2016). Altered Mental Status in Children.. Retrieved June 16, 2018 from
  • Hosley, C. M., & McCullough, L. D. (2011). Acute neurological issues in pregnancy and the peripartum. The Neurohospitalist1(2), 104-116.




Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.