This decrease is often characterized by sluggishness and lethargy. These shifts may cause emotional disturbances. Emotional disturbances are very common with the onset of delirium. Anxiety, fear or depression, irritability, anger, euphoria and apathy may exist. Rapid and unpredictable shifts between these emotions are likely.
Fear often accompanies threatening hallucinations or perceived threatening injuries.
Persons with delirium may call out or scream because they fear falling or some other type of injury. Emotional disturbances are especially prevalent at night or under conditions in which there is a lack of stimulation or environmental cues. Predisposing factors of delirium are different for different ages. Infection A common cause of the disorder is a certain type of infection. Those with metabolic disorders, non-malignant central nervous system disease, heart disease and endocrine disorders are likely to develop Delirium.