Liver failure
Inborn errors of metabolism with urea cycle defects and organic acidemia
Shock, severe dehydration
Renal failure
Gastrointestinal bleeding
Urinary tract infection with a urease-producing organism (i.e. proteus mirabilis), systemic infection with mycoplasma hominis or ureasplasma species in lung transplant patients
Reye syndrome
Any cause of portosystemic shunting of blood
Ureterosigmoidostomy
Cigarette smoking
Transient<unk>  in newborns
Parenteral nutrition
Medication toxicity, including:
High dose chemotherapy
Valproic acid
Barbiturates
ETOH intoxication|ETOH]]
Diuretics
ASA
Glycine toxicity
High dose chemotherapy
Valproic acid
Barbiturates
ETOH intoxication|ETOH]]
Diuretics
ASA
Glycine toxicity
Hypoxic encephalopathy
Acute toxic-metabolic encephalopathy (Delirium)
Hypoglycemia
Hyperosmolar state (e.g., hyperglycemia)
Electrolyte Abnormalities (hypernatremia or hyponatremia, hypercalcemia)
Organ system failure
Hepatic Encephalopathy
Uremia/Renal Failure
Endocrine (Addison's disease, Cushing syndrome, hypothyroidism, myxedema coma, thyroid storm)
Hypoxia
CO2 narcosis
Hypertensive Encephalopathy
Toxins
TTP / Thrombotic thrombocytopenic purpura
Alcohol withdrawal
Drug reactions (NMS, Serotonin Syndrome)
Environmental causes
Hypothermia
Hyperthermia
Deficiency state
Wernicke encephalopathy
Subacute Combined Degeneration of Spinal Cord (B12 deficiency)
Vitamin D Deficiency
Zinc Deficiency
Sepsis
Osmotic demyelination syndrome (central pontine myelinolysis)
Limbic encephalitis
Hypoglycemia
Hyperosmolar state (e.g., hyperglycemia)
Electrolyte Abnormalities (hypernatremia or hyponatremia, hypercalcemia)
Organ system failure
Hepatic Encephalopathy
Uremia/Renal Failure
Endocrine (Addison's disease, Cushing syndrome, hypothyroidism, myxedema coma, thyroid storm)
Hypoxia
CO2 narcosis
Hypothermia
Hyperthermia
Wernicke encephalopathy
Subacute Combined Degeneration of Spinal Cord (B12 deficiency)
Vitamin D Deficiency
Zinc Deficiency
Direct CNS trauma
Diffuse axonal injury
Subdural/epidural hematoma
Vascular disease
Intraparenchymal hemorrhage
SAH
Stroke
Hemispheric, brainstem
CNS infections
Encephalitis
Anti-NMDA receptor encephalitis
Meningitis
Neoplasms
Paraneoplastic Limbic encephalitis
Malignant Meningitis
Pancreatic Insulinoma
Seizures
Nonconvulsive status epilepticus
Postictal state
Dementia
Alzheimer's
Lewy Body Dementia
Frontotemporal Dementia
Diffuse axonal injury
Subdural/epidural hematoma
Intraparenchymal hemorrhage
Hemispheric, brainstem
Encephalitis
Anti-NMDA receptor encephalitis
Meningitis
Paraneoplastic Limbic encephalitis
Malignant Meningitis
Pancreatic Insulinoma
Nonconvulsive status epilepticus
Postictal state
Alzheimer's
Lewy Body Dementia
Frontotemporal Dementia
Acute psychosis
Catatonia
Excited delirium
Malingering
Hyperammonemia
Liver failure
Ketonemia
Inborn errors of metabolism with urea cycle defects and organic acidemia
Lactic acidosis
Shock, severe dehydration
Ketoacidosis
Renal failure