What causes delirium?
There are a large number of possible causes of delirium. Metabolic disorders are the single most common cause, accounting for 20–40% of all cases. This type of delirium, termed "metabolic encephalopathy," may result from organ failure, including liver or kidney failure. Other metabolic causes include diabetes mellitus, hyperthyroidism and
hypothyroidism, vitamin deficiencies, and imbalances of fluids and electrolytes in the blood. Severe dehydration can also cause delirium.
Drug intoxication ("intoxication confusional state") is responsible for up to 20% of delirium cases, either from side effects, overdose, or deliberate ingestion of a mind-altering substance. Medicinal drugs with delirium as a possible side effect or result of overdose include: Anticholinergics, including atropine, scopolamine, chlorpromazine (an antipsychotic), and diphenhydramine (an antihistamine)
Sedatives, including barbiturates, benzodiazepines, and ethanol (drinking alcohol)
Nonsteroidal anti-inflammatory drugs (NSAIDs), including ibuprofen and acetaminophen
Corticosteroids, including prednisone
Anticancer drugs, including methotrexate and procarbazine
Delirium may result from ingestion of legal or illegal psychoactive drugs, including: Ethanol (drinking alcohol)
LSD (lysergic acid diethylamide) and other hallucinogens
Opiates, including heroin and morphine
Drug withdrawal may also cause delirium. Delirium tremens, or "DT's," may occur during alcohol withdrawal after prolonged or intense consumption. Withdrawal symptoms are also possible from many of the psychoactive prescription drugs.
Poisons may cause delirium ("toxic encephalopathy"), including:Solvents, such as gasoline, kerosene, turpentine, benzene, and alcohols
Heavy metals, such as lead, mercury, and arsenic
Insecticides, such as Parathion and Sevin
Mushrooms, such as Amanita species
Plants such as jimsonweed (Datura stramonium) and morning glory (Ipomoea spp.)
Other causes of delirium include: Infection
Brain hemorrhage or infarction
Low blood oxygen (hypoxemia)
High blood carbon dioxide (hypercapnia)