Delirium is a clinical state characterized by an acute change in a person’s mental status. It usually comes on quickly, over hours or days. It is marked by extreme, fluctuating changes, including:

  • Changes in perception and sensation
  • Difficulties with ability to:
    • Focus
    • Sustain and shift attention
    • Think and reason rationally
    • Function normally
    • Communicate clearly


Hundreds of underlying causes can result in delirium. Some of the most common causes include:


Risk Factors

These factors increase your chance of developing delirium:

  • Having a terminal illness (eg, cancer), especially just prior to death
  • Having a serious illness (eg, AIDS]]> , ]]>dementia]]> )
  • Being of an advanced age
  • Being severely sleep deprived
  • Having a severe ]]>burn]]>
  • Having central nervous system problems (eg, ]]>stroke]]> , ]]>seizures]]> , or tumors)
  • Being:
    • Visually or hearing impaired
    • Immobile
    • ]]>Dehydrated]]>
    • Constipated
    • Memory impaired
    • Deficient in vitamins



Symptoms usually come on quickly. They can vary in severity, depending on the underlying cause. They can last for days, weeks, or longer. Symptoms are often worse at night and may include:

  • Inability to pay attention
  • Confusion
  • Memory problems
  • Language disturbances
  • Disorientation, especially in regard to:
    • Time of day
    • Where one is
    • Who one is
  • Severe symptoms include:
    • Misinterpretations—for example, thinking a doctor who is trying to help you is trying to hurt you
    • Illusions—for example, thinking someone is someone else
    • Hallucinations—seeing, hearing, or feeling things that aren’t there
    • Emotional disturbances—such as suddenly becoming very angry, fearful, or withdrawn for no apparent reason


The doctor will ask about your symptoms and medical history, and perform a thorough physical exam. The doctor will ask specific questions about:

  • Present injury or illness
  • Use of medications or illicit drugs
  • Time when mental state changed
  • How and how fast the mental state changed

There are many tests that may be used to help diagnose delirium. Depending on the specific case, any or all of these tests may be done, including:

  • Blood electrolytes—to measure levels of sodium , potassium , and calcium
  • Kidney and liver function tests
  • Blood glucose levels
  • Complete blood count (CBC)
  • Blood vitamin levels—such as vitamin B12 and folate
  • Thyroid function tests
  • Blood cultures—to look for signs of infection
  • Spinal fluid culture]]> —to look for signs of infection
  • Urine examination and culture—to look for signs of infection
  • Arterial blood gas—to check oxygen levels in the blood
  • Toxicology testing—to search for any illicit drugs in the body
  • Blood levels of medications
  • ]]>Chest x-ray]]> —a test that uses radiation to take a picture of structures inside the chest to look for signs of pneumonia
  • ]]>Electrocardiogram]]> (ECG, EKG)—a test that records the heart's activity by measuring electrical currents through the heart muscle
  • ]]>CT scan]]> —a type of x-ray that uses a computer to make pictures of structures inside the head
  • ]]>MRI scan]]> —a test that uses magnetic waves to make pictures of structures inside the head
  • ]]>Electroencephalogram]]> (EEG)—a test that record's the brain's activity by measuring electrical currents through the brain



Delirium is first treated by identifying and treating the underlying cause. Then, symptoms are treated through medications, psychological management, and environmental and supportive intervention.

Treatments may include:


Drugs used to treat symptoms of delirium include:

  • High potency antipsychotic medications (eg, haloperidol]]> [Haldol])
  • Benzodiazepines—used to treat delirium caused by alcohol withdrawal
  • Cholinergic medications—used to treat delirium caused by anticholinergic medications, which are used to treat stomach cramps and spasms in the intestines and bladder, among other treatments
  • Vitamins—specific vitamin supplements are given if the delirium is caused by a deficiency

If you are taking medications that are worsening your confusion, then your doctor may either stop these.

Psychologic Management

This type of therapy involves helping the patient to:

  • Feel more safe and comfortable
  • Identify the cause of the delirium
  • Improve the ability to function
  • Calm down and feel less ]]>anxious]]>

Environmental and Supportive Intervention

This type of treatment can be done by doctors, nurses, or caretakers. It is aimed at reorienting you to the surroundings and reducing anxiety. It can involve actions, such as:

  • Placing a clock and calendar in your room
  • Darkening the room at night and providing natural light during the day time hours
  • Maintaining a quiet, noise-free room
  • Reminding you often of the day and time, where you are, and why you are there
  • Placing familiar objects around you (eg, family photographs or objects from home)


A number of steps have been shown to help prevent delirium in hospitalized patients at risk for delirium. These steps include:

  • Using memory orientation aids
  • Listening to relaxation tapes
  • Doing very light exercise (when possible and if recommended by your doctor)
  • Using vision and hearing aids (when necessary)
  • Drinking plenty of fluids (to prevent dehydration)

Delirium is difficult to prevent because it has so many causes and it can come on suddenly.