Delirium is a medical term. The condition is also known as acute confusional state. But, this term is not frequently used anymore, because this term can have many different meanings. Doctors use it to describe patients who have lost parts or all of their ability to focus attention. People who suffer from it may also have problems to concentrate, or to remember things or other people. Delirium is a medical symptom. It is not a disease. Delirium is also considered a type of confusion, but a more severe one, than simple weaker confusion. Delirium can be caused by many things, like anticholinergic medications, too much alcohol, and benzodiazepine medications. Delirium can be confused with other mental conditions like Schizophrenia, Dementia and Psychosis, because all of these conditions have symptoms similar to Delirium.