Delirium is a sudden change in your alertness and thinking. People with delirium typically become confused and have trouble paying attention.

Delirium is an abrupt change to your mental state. It makes it difficult to think, remember, focus, and more. Some people with delirium become drowsy and quiet, while others can become agitated.

Symptoms of delirium generally appear quickly over a period of hours or days. The symptoms tend to fluctuate, meaning they are more severe at some times, and less severe at others.

You might experience delirium due to illness, infection, or medication side effects, among other reasons.

Delirium is a serious condition, but it’s often temporary. Your doctor will treat delirium by finding and treating the underlying causes.

Delirium is categorized by its cause and characteristics.

Hypoactive delirium

People with hypoactive delirium may be:

  • unusually drowsy or sleepy
  • unable to focus or pay attention
  • quiet and withdrawn
  • slower than usual when moving their body

Hyperactive delirium

People with hyperactive delirium may:

  • appear agitated or anxious
  • speak fast or loud
  • become restless, or unable to sit still
  • respond negatively or aggresively to caregivers
  • seem watchful or paranoid

Mixed delirium

Mixed delirium is a combination of both hyperactive and hypoactive delirium. People with mixed delirium have hyperactive delirium symptoms at some times, and hypoactive delirium symptoms at other times.

Alcohol withdrawal delirium

Alcohol withdrawal delirium, or delirium tremens, is a form of the condition that can happen to people who drink large amounts of alcohol for many years. If someone who regularly drinks a lot suddenly tries to stop drinking, severe withdrawal including delirium is possible.

Delirium tremens is a medical emergency that requires immediate treatment to prevent severe complications. If it’s left untreated, it can be fatal in up to 37% of cases. Fortunately, early treatment greatly improves the outcomes.

Delirium happens when stressors like inflammation or infection interfere with your brain function. There are many possible causes.

The condition is very common among older adults who need hospital care. Around one-third of hospital patients over age 70 experience delirium at some point during their hospital stay. It’s possible for younger people to experience delirium too, although it’s less common.

Any condition or factor that significantly changes your brain function can cause severe mental confusion. These include:

Medication side effects are a major cause of delirium. Up to 39% of the time, delirium is caused by medications.

In general, older adults with multiple health conditions are more likely to experience delirium. But it can happen in younger people, too.

Factors that may increase your risk for delirium include:

  • dementia, or symptoms of dementia without a formal diagnosis
  • age older than 70
  • male sex
  • a disability that makes it difficult to carry out basic tasks of living
  • living with multiple health conditions
  • impaired hearing or vision
  • mild cognitive impairment
  • symptoms of depression
  • alcohol use disorder
  • abnormal results on laboratory tests, such as blood or urine tests

Delirium affects your mind, emotions, movements, and sleep patterns.

You might have a hard time concentrating or feel confused about what’s happening around you. You may also move more slowly or quickly than usual, and experience mood swings.

Other symptoms may include:

  • not thinking clearly
  • having trouble speaking clearly or participating in a conversation
  • being easily distracted
  • losing track of what time it is and where you are (disorientation)
  • sleeping poorly or feeling drowsy
  • sudden changes in your ability to carry out everyday activities, like eating or walking
  • difficulty remembering recent events
  • becoming agitated or paranoid

If alcohol withdrawal progresses to delirium, symptoms may include:

A healthcare professional can diagnose you with delirium. Usually, this is done by a doctor or, in some cases, a nurse.

The clinician will observe your symptoms and examine you to see how you think, speak, and move.

Confusion assessment method

Many health professionals use the Confusion Assessment Method (CAM) to diagnose or rule out delirium. This is a screening test that helps them observe whether or not:

  • your behavior and mental state is fluctuating over time
  • you have a hard time paying attention or following others as they speak
  • you have trouble keeping your thoughts organized
  • you’re experiencing an altered state of alertness

Tests and exams

Many factors can cause changes in brain chemistry and function. Your doctor will try to determine the cause of the delirium by running tests relevant to your symptoms and medical history.

One or more of the following tests may be needed to check for underlying causes:

Your doctor may also request other tests, depending on your symptoms.

Depending on the cause of the delirium, treatment may include taking or stopping certain medications.

In older adults, an accurate diagnosis is important for treatment, as delirium symptoms are similar to dementia, but the treatments are very different.


Your doctor may prescribe medications to treat the underlying cause of your delirium. For example, if your delirium is caused by a severe asthma attack, you might need an inhaler to restore your breathing.

If a bacterial infection is causing the delirium symptoms, antibiotics may be prescribed.

In some cases, your doctor may recommend that you stop taking certain medications if they are causing delirium.

If you are experiencing substance withdrawal, you may be prescribed medication to manage your symptoms.

Delirium itself is not usually treated with medication. Rather, it is the underlying cause that is being treated. But if you have severe symptoms of hyperactive delirium that do not improve, antipsychotic medications may be considered.

Supportive care

Reducing stress and creating a calm environment can help you recover from delirium. You may find it helpful to:

  • set a clear daily routine
  • eat and drink water on a regular schedule
  • keep clocks and calendars visible to orient yourself
  • maintain good sleep habits
  • be physically active in ways that are safe for you
  • put on your glasses and hearing aids daily, if you use these devices

If you are caring for someone with delirium, do your best to:

  • speak calmly and use short sentences
  • reassure them
  • avoid moving your loved one to an unfamiliar room or place during recovery, if it’s not necessary
  • share familiar objects, like photos


If you’re feeling disoriented, counseling may help to anchor your thoughts.

Counseling is also used as a treatment for people whose delirium was brought on by substance use. In these cases, the treatment can help you abstain from using the substances that brought on the delirium.

In all cases, counseling is intended to make you feel comfortable and give you a safe place to discuss your thoughts and feelings.

Recovering from delirium takes time. It can take weeks or months for you to think, speak, and feel physically like your old self. Sometimes, certain changes may be permanent. The course of recovery is different for everyone.

To reduce the chance of delirium coming back, follow your treatment plan carefully to address underlying causes. Do your best to avoid stress and maintain health-promoting habits, such as eating well, drinking lots of water, and getting quality sleep.

Delirium can often go unrecognized. If you notice a changed mental state or level of alertness in yourself or your loved one, it’s important to talk with a doctor. Sudden changes may be a sign of a medical emergency.