Mental Confusion or Delirium

Approved by the Cancer.Net Editorial Board, 06/2016

Delirium is a cognitive impairment disorder, meaning that it affects how a person thinks, remembers, and reasons. The main signs are sudden changes in consciousness or state of arousal, such as feeling drowsy or agitated.

A person with delirium may experience confusion, disorientation, an inability to focus, memory problems, or changes in perception. These can include hallucinations or experiencing events that aren’t really happening.

Delirium is the most common sign of medical complications of cancer or cancer treatment affecting the brain and mind. It is a common problem for people with advanced cancer or those at the end of life. Because of its troubling symptoms, delirium is often very stressful for the patient and family members.

In addition, delirium complicates the ability of the health care staff to assess and manage a person’s other symptoms. It can also interfere with a patient’s ability to receive cancer treatments.

Types of delirium

There are three types of delirium:

  • Hypoactive, meaning that the person acts sleepy or withdrawn

  • Hyperactive, meaning that a person is agitated

  • Mixed, meaning that a person alternates between these two types

More than two thirds of patients with delirium have the hypoactive or mixed type. A patient may experience hallucinations and delusions with any of the types.

Symptoms of delirium

Symptoms of delirium include the following:

  • An altered level of consciousness or awareness

  • A shortened attention span

  • Memory problems

  • Disorganized thinking and speech

  • Disorientation

  • A reversal of day and night

  • Difficulty writing, drawing, or finding words

  • Personality changes

  • Depression

  • Delusions or hallucinations

  • Restlessness, anxiety, sleep disturbance, or irritability

Causes of delirium

Delirium often has more than one cause especially for those who are frail or severely ill. Medications are one of the main causes of delirium, but many other conditions can lead to delirium. Therefore, finding the cause of delirium is important to choose the best treatment.

The following are possible causes of delirium:  

  • Medications

    • Chemotherapy

    • Pain medications

    • Medications for other symptoms or side effects

      • Antinausea

      • Steroids

      • Sleep

      • Allergy blocking

    • New medications for other conditions

    • Withdrawal from medication

  • Organ dysfunction

    • Liver

    • Kidney

    • Lung

    • Heart

    • Brain

      • Metastases

      • Leptomeningeal disease, which affects the two inner layers that cover the brain

      • Seizure disorder

  • Fluid and electrolyte imbalances

    • Hypercalcemia, which is too much calcium in the blood 

    • Dehydration   

      • Lack of fluid intake from nausea, vomiting or inability to swallow

      • Loss of fluids

        • Diarrhea

        • Frequent urination

    • Fluid overload

      • Heart failure

    • Glucose disorder

      • Hyperglycemia, which is a high blood sugar level

        • From diabetes worsened by treatments or in people with no history of diabetes

      • Hypoglycemia, which is a too low blood sugar level

  • Infection

  • Lack of oxygen in the blood

    • Lung or heart disorder

    • Blood clots to lung

Diagnosing delirium

To find out whether a patient is experiencing delirium, doctors must do a physical exam and blood tests. They will also do a mental status exam, using tests that check motor skills, memory, and attention level. Your doctor may also recommend other tests, such as brain scans, based on the results of testing.

Managing delirium

The most effective treatment for delirium is to understand and treat the cause. The doctor may use drug and non-drug approaches to manage delirium while keeping the patient comfortable and safe. It is important to work with the health care team to manage the symptoms of delirium. These tips may help:

  • Provide a reassuring environment for the patient, such as a quiet, well-lit room with familiar people and objects. It may also help to place a clock and wall calendar where a patient can see it.

  • Talk with the doctor, nurse, or another member of the health care team about a patient’s hallucinations or unusual behaviors. The health care team can help you learn what to expect and how to manage these symptoms.

  • Ask about stopping or switching medications that may worsen a patient’s mental confusion. Also, ask if there are other, untreated medical conditions that may be the cause of delirium.

  • In some cases, giving antipsychotic medications helps control the symptoms of delirium. Although these drugs can have side effects, most can be managed well.

Relieving side effects is an important part of cancer care and treatment. This is called symptom management or palliative care. Talk with your health care team about any symptoms of delirium you or the person you care for experiences. This includes any new symptoms or a change in symptoms.

Delirium at the end of life

Delirium at the end of life is common. Some believe that the hallucinations at the end of life are a part of the dying process and should not be treated. For example, patients who see dead family members welcoming them to an afterlife may find great comfort. However, if the delirium is unpleasant or frightening to the patient, treatment can be of great benefit.

Unpleasant delirium or delirium that causes other symptoms can be managed with several medications. These are often adjusted to help control the delirium but not interfere with the patient’s ability to interact with others.

Very rarely, a person with severe, agitated delirium that doesn’t get better with treatment may need controlled sedation. Sedation is the use of drugs that put a patient into a deep sleep. This makes the patient and the family more comfortable. However, it may leave family members with a premature sense of loss. Sedation is used to provide comfort to a patient and the family at the end of life. It is not intended to speed up death. Even with sedation, a patient may experience moments of clarity and talk with family members.

Each decision about managing delirium depends on the individual. It is important for patients and their family members to talk with the health care team about all of the available treatment options.

More Information

Care Through the Final Days

Side Effects