Delirium describes a gradual loss of the ability to focus or pay attention combined with perceptual difficulties and the ability to think clearly and logically. It differs from dementia in that the condition develops over a shorter period of time (from hours to days) and is often temporary. Delirious patients can either be very hyperactive or even aggressive, but can also remain in a quiet state. Delirious patients generally do not suffer from hallucinations or delusions.
For example, a delirious patient may:
- Have difficulty paying attention to the doctor or family members.
- Be unable to carry on a conversation
- Be unable to see objects across the room
- Be unable to clearly understand instructions given to them
- Be unable to solve simple problems
Delerium can be caused by dozens of medical conditions and, by itself, is not diagnostically specific. It is not limited to cases of mental illness but also can be a sign of organic illnesses. Some of the conditions that present with delerium are critical illness, drug withdrawal, head trauma, sleep disturbances such as insomnia, hypoxia, hypoglycemia, alcohol and medication.