Delirium is a serious disturbance in a person's mental abilities that results in a decreased awareness of one's environment and confused thinking. The onset of delirium is usually sudden, often within hours or a few days.
Delirium can often be traced to one or more contributing factors, such as a severe or chronic medical illness, medication, infection, surgery, or drug or alcohol abuse.
The symptoms of delirium and dementia can be similar, and input from a family member or caregiver may be important for a doctor to make an accurate diagnosis.
The signs and symptoms of delirium appear over a short period of time, from a few hours to a few days. They often fluctuate throughout the day, so a person may have periods of no symptoms. Primary signs and symptoms include those below.
Reduced awareness of the environment
Poor thinking skills (cognitive impairment)
Delirium and dementia
Dementia is the progressive decline of memory and other thinking skills due to the gradual dysfunction and loss of brain cells. The most common cause of dementia is Alzheimer's disease.
Some differences between the symptoms of delirium and dementia include:
When to see a doctor
Older people recovering in the hospital or living in a long-term care facility are particularly at risk of delirium. Because symptoms can fluctuate and some symptoms are "quiet" — such as social withdrawal or poor responsiveness — delirium may be missed. If you notice signs and symptoms of delirium in a person in a hospital or nursing home, report your concerns to the nursing staff or doctor rather than assuming that those problems have been observed.
Delirium occurs when the normal sending and receiving of signals in the brain becomes impaired. This impairment is most likely caused by a combination of factors that make the brain vulnerable and trigger a malfunction in brain activity.
Any condition that results in a hospital stay, especially in intensive care, increases the risk of delirium. Common causes include dehydration and infections, such as urinary tract infection, pneumonia, and skin and abdominal infections. Examples of other conditions that increase the risk of delirium include:
A number of medications or combinations of medications can trigger delirium, including some types of:
Delirium may have more than one cause, such as a medical condition and medication toxicity.
Delirium may last only a few hours or as long as several weeks or months. If factors contributing to delirium are addressed, the recovery time is often shorter.
The degree of recovery depends to some extent on the health and mental status before the onset of delirium. People with dementia, for example, may experience a significant overall decline in memory and thinking skills. People in better health are more likely to recover fully.
People with other serious, chronic or terminal illnesses may not regain the levels of thinking skills or functioning that they had before the onset of delirium. Delirium in seriously ill people is also more likely to lead to:
Preparing for your appointment
If you're the relative or primary caregiver of a person with delirium, you'll likely play a role in making an appointment or providing information to the doctor.
What you can do
What to expect from the doctor
Tests and diagnosis
A doctor will diagnose delirium based on the answers to questions about a person's medical history, tests to assess mental status and the identification of possible contributing factors. An examination may include the following:
Treatments and drugs
The first goal of treatment for delirium is to address any underlying causes or triggers — by stopping use of a particular medication, for example, or treating an infection. Treatment then focuses on creating the best environment for healing the body and calming the brain.
A number of simple, nondrug approaches may be of some help:
Coping and support
If you're a relative or caregiver of someone at risk of or recovering from delirium, you can take steps to improve the person's health, prevent a recurrence and help manage responsibilities.
Promote good sleep habits
Promote calmness and orientation
Prevent complicating problems
Caring for the caregiver
Examples of organizations that may provide helpful information include the National Family Caregivers Association and the National Institute on Aging.
The most successful approach to preventing delirium is to target risk factors that might trigger an episode. Hospital environments present a special challenge — frequent room changes, invasive procedures, loud noises, poor lighting and lack of natural light can worsen confusion.
Evidence indicates that these strategies help prevent or reduce the severity of delirium in hospitalized people:
Last Updated: 2012-08-15
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