In medicine, confusion is the quality or state of being bewildered or unclear. The term "acute mental confusion"''Confusion Definition''
on Oxford Dictionaries. is often used interchangeably with

delirium Delirium (also known as acute confusional state) is an organically caused decline from a previous baseline of mental function that develops over a short period of time, typically hours to days. Delirium is a syndrome encompassing disturbances in ...

in the ''

International Statistical Classification of Diseases and Related Health Problems The International Classification of Diseases (ICD) is a globally used diagnostic tool for epidemiology, health management and clinical purposes. The ICD is maintained by the World Health Organization (WHO), which is the directing and coordinating ...

'' and the ''

Medical Subject Headings Medical Subject Headings (MeSH) is a comprehensive controlled vocabulary for the purpose of indexing journal articles and books in the life sciences. It serves as a thesaurus that facilitates searching. Created and updated by the United States N ...

'' publications to describe the pathology. These refer to the loss of

orientation Orientation may refer to: Positioning in physical space * Map orientation, the relationship between directions on a map and compass directions * Orientation (housing), the position of a building with respect to the sun, a concept in building de ...

, or the ability to place oneself correctly in the world by time, location and personal identity. Mental confusion is sometimes accompanied by disordered consciousness (the loss of linear thinking) and memory loss (the inability to correctly recall previous events or learn new material).confusion
in TheFreeDictionary, citing: Dorland's Medical Dictionary for Health Consumers; 2007; Saunders.

Etymology

The word confusion derives from the Latin word, ''confundo'', which means "confuse, mix, blend, pour together, disorder, embroil."

Causes

Confusion may result from drug side effects or from a relatively sudden brain dysfunction. Acute confusion is often called

(or "acute confusional state"), although delirium often includes a much broader array of disorders than simple confusion. These disorders include the inability to focus attention; various impairments in awareness, and temporal or spatial dis-orientation. Mental confusion can result from chronic organic brain pathologies, such as dementia, as well.

Other

* Acute stress reaction * Alcoholism * Anemia * Anticholinergic toxicity * Anxiety *

Brain damage Neurotrauma, brain damage or brain injury (BI) is the destruction or degeneration of brain cells. Brain injuries occur due to a wide range of internal and external factors. In general, brain damage refers to significant, undiscriminating t ...

* Brain tumor *

Concussion A concussion, also known as a mild traumatic brain injury (mTBI), is a head injury that temporarily affects brain functioning. Symptoms may include loss of consciousness (LOC); memory loss; headaches; difficulty with thinking, concentration, ...

* Dehydration * Encephalopathy * Epileptic seizure * Depression *

Fatigue Fatigue describes a state of tiredness that does not resolve with rest or sleep. In general usage, fatigue is synonymous with extreme tiredness or exhaustion that normally follows prolonged physical or mental activity. When it does not resolve ...

* Fever * Brain injury * Heat stroke * Hypoglycemia * Hypothermia *

Hypothyroidism Hypothyroidism (also called ''underactive thyroid'', ''low thyroid'' or ''hypothyreosis'') is a disorder of the endocrine system in which the thyroid gland does not produce enough thyroid hormone. It can cause a number of symptoms, such as po ...

* Jet lag * Kidney failure * Kidney infection ( pyelonephritis) * Lactic acidosis * Lassa fever * Lewy body dementia * Listeria * Lyme disease *

Meningitis Meningitis is acute or chronic inflammation of the protective membranes covering the brain and spinal cord, collectively called the meninges. The most common symptoms are fever, headache, and neck stiffness. Other symptoms include confusion or ...

* Postpartum depression & Postpartum psychosis * Psychotic Disorder * Reye's syndrome * Rocky Mountain spotted fever (RMSF) * Schizophrenia *

Sick building syndrome Sick building syndrome (SBS) is an unsubstantiated diagnosis where health problems are attributed to buildings. The cause of the health problems are unknown. Symptoms attributed to SBS may or may not be a direct result of inadequate cleaning or ...

* Sleep apnea *

Stroke A stroke is a medical condition in which poor blood flow to the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functionin ...

* Yellow fever * STDs & STIs *

Streptococcal ''Streptococcus'' is a genus of gram-positive bacteria, gram-positive ' (plural ) or spherical bacteria that belongs to the family Streptococcaceae, within the order Lactobacillales (lactic acid bacteria), in the phylum Bacillota. Cell divisio ...

Infections * Toxicity * Toxic shock syndrome * Transient ischemic attack (TIA, Mini-Stroke) *

Vitamin B₁₂ deficiency A vitamin is an organic molecule (or a set of molecules closely related chemically, i.e. vitamers) that is an essential micronutrient that an organism needs in small quantities for the proper functioning of its metabolism. Essential nutrien ...

* Acute Porphyria * West Nile virus

Differential diagnosis

The most common causes of drug induced acute confusion are

dopaminergic Dopaminergic means "related to dopamine" (literally, "working on dopamine"), dopamine being a common neurotransmitter. Dopaminergic substances or actions increase dopamine-related activity in the brain. Dopaminergic brain pathways facilitate d ...

drugs (used for the treatment of Parkinson's disease), diuretics, tricyclic,

tetracyclic antidepressants Tetracyclic antidepressants (TeCAs) are a class of antidepressants that were first introduced in the 1970s. They are named after their tetracyclic chemical structure, containing four rings of atoms, and are closely related to the tricyclic a ...

and

benzodiazepines Benzodiazepines (BZD, BDZ, BZs), sometimes called "benzos", are a class of depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed to treat conditions such as anxiety disorders, i ...

alcohol Alcohol most commonly refers to: * Alcohol (chemistry), an organic compound in which a hydroxyl group is bound to a carbon atom * Alcohol (drug), an intoxicant found in alcoholic drinks Alcohol may also refer to: Chemicals * Ethanol, one of sev ...

. The elderly, and especially those with pre-existing dementia, are most at risk for drug induced acute confusional states. New research is finding a link between vitamin D deficiency and cognitive impairment (which includes "foggy brain").

References

External links