Delirium This is an acute state of mental confusion that occurs rapidly, causing clouding of consciousness (the person is in a "stupor"), decreased mental function (often shifting from good to bad periods), and difficulty with attention and concentration. Clouded consciousness (person is in a stupor) Lack of attention Difficulty concentrating Disoriented Medications such as corticosteroids and Valium Hypoxia (decreased oxygenation) Hypoglycemia (low blood sugar) Illegal drug intoxication Alcohol intoxication Alcohol withdrawal Infections such as Meningitis Metabolic imbalances Kidney disease Liver disease Vitamin deficiencies Brain Injuries such as Acute Subdural Hematoma Prolonged hospitalization ("intensive care unit psychosis") "Sundowning" -- elderly individuals get confused at nighttime only Wernicke's Encephalopathy Thyroid disorders Endocrine disorder Post-seizure states Blood work to rule out infections, as well as metabolic and endocrinological causes Alcohol and drug screening Lumbar puncture (spinal tap) CT scan or MRI scan Treat the underlying cause Seek immediate emergency medical attention as the causes usually can be treated.  Untreated, many of the causes can lead to permanent disability, Coma, or death. Depression Schizophrenia Dementia Delirium versus Dementia Delirium occurs rapidly, causing the mind to be clouded (in a stupor). Dementia occurs slowly, leaving the mind relatively clear (the person is confused and has memory loss, but he is not sleepy or in a stupor). Delirium may occur in an individual with Dementia.