00:00 / 00:00




Psychological disorders

Bipolar and related disorders

Bipolar disorder

Feeding and eating disorders

Anorexia nervosa

Bulimia nervosa

Medication-induced movement disorders and other adverse effects of medication

Neuroleptic malignant syndrome

Serotonin syndrome

Somatic symptom and related disorders

Factitious disorder

Somatic symptom disorder

Trauma and stressor-related disorders; Abuse

Physical and sexual abuse

Post-traumatic stress disorder




0 / 13 complete

High Yield Notes

4 pages



of complete

External References

First Aid








Anticholinergic drugs

delirium with p. 581

Delirium p. 581

barbiturate withdrawal p. 594

diabetic ketoacidosis p. 357

PCP p. 595

thyroid storm p. 348

Geriatric patients

drug-related delirium in p. 581

Hallucinations p. 582

delirium p. 581

Haloperidol p. 597

delirium p. 581


delirium caused by p. 581

Sleep problems

delirium and p. 581

Substance abuse

delirium with p. 581

Urinary retention

delirium p. 581


Content Reviewers

Delirium is a common and very serious neuropsychiatric syndrome.

Typically it affects older patients with multiple medical problems, in fact up to half of all elderly patients in the hospital will have an episode of delirium at some point, but being said it can affect anyone - even children, even though that’s much less common.

So, what is delirium exactly? Well let’s look at a quick example. Let’s say there is an elderly man with diabetes and heart disease, who comes into the hospital with pneumonia.

He might be slowly recovering, even about to go home, and then one evening things change all of the sudden. He might get really hyperactive, and by that I mean that he may get agitated or aggressive with the staff, mumble or say things incoherently, and have disorganized thoughts or even delusions, perhaps talking about things that haven’t happened or happened years ago. He might even hear or see things like hallucinations, and not know where he is or what he’s doing there.

We would call this an episode of delirium, and it can be really scary for him or someone who is taking care of him, especially the first time it happens because it can come out of the blue.

These are the symptoms of what we call hyperactive delirium.

But there’s also hypoactive delirium which is like the flip side of the coin.

As an example, you might have a woman with a history of chronic constipation who has recently come out of back surgery.

If she has hypoactive delirium she might feel suddenly sluggish and drowsy, less reactive and sullen, and might look withdrawn, perhaps because she’s scared of having hallucinations.

These symptoms of both hyperactive and hypoactive delirium can start pretty suddenly and can happen off and on over the course of a few hours to a few days, with some patients having what they call mix state delirium where they are sometimes having hyperactive symptoms and sometimes having hypoactive symptoms.

As you might guess, delirium symptoms can be really tiresome for a patient and can make them sleepy during the day, and keep them up at night - all of which causes massive disruption to a person’s life and to the lives of their friends and family.


Copyright © 2023 Elsevier, its licensors, and contributors. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Cookies are used by this site.

USMLE® is a joint program of the Federation of State Medical Boards (FSMB) and the National Board of Medical Examiners (NBME). COMLEX-USA® is a registered trademark of The National Board of Osteopathic Medical Examiners, Inc. NCLEX-RN® is a registered trademark of the National Council of State Boards of Nursing, Inc. Test names and other trademarks are the property of the respective trademark holders. None of the trademark holders are endorsed by nor affiliated with Osmosis or this website.