While dementia and delirium have a few similarities, delirium comes on quickly and involves rapid symptom changes.

Dementia is a broad term that covers a range of degenerative conditions that causes symptoms such as confusion, memory loss, personality changes, and loss of impulse control.

Delirium is a condition that comes on suddenly and causes symptoms such as disorientation, confusion, communication difficulties, and agitation.

These two conditions share similarities, but they aren’t the same. Recognizing the difference between these two conditions is important because delirium symptoms may be the result of a medical emergency requiring quick medical attention.

Delirium and dementia both cause a person to become confused and display significant behavioral changes.

Delirium is a sudden worsening of a person’s mental state. It can develop over the course of hours or days, typically as a symptom of an underlying condition, like an infection. People with delirium experience symptoms that can fluctuate throughout the day, such as:

When to seek emergency care for delirium

Delirium always needs medical attention. If someone starts displaying symptoms of delirium, seek urgent medical care.

It’s important to have delirium evaluated so that the underlying cause can be treated quickly.

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Dementia is a chronic condition that develops slowly over time. It’s a degenerative condition and gets worse over time. Symptoms start out mild and get more severe as the condition progresses. Treatments can sometimes slow the progress of dementia, but there’s no cure.

People with dementia may forget:

  • recent events
  • older memories and events
  • names of familiar people and places

Other symptoms of dementia include:

  • getting lost in familiar locations
  • difficulty controlling impulses and emotions
  • severe mood shifts
  • personality changes
  • confusion
  • loss of problem-solving skills
  • difficulty completing self-care tasks
  • difficulty communicating
  • anxiety and paranoia
  • incontinence

Dementia and delirium have a few similarities. Both can cause:

  • confusion
  • difficulties with communication
  • extreme emotional expressions
  • paranoia
  • hallucinations

Additionally, both conditions are more common as people age. Being over the age of 65 is a risk factor for dementia and delirium.

The causes of delirium and dementia are very different. Dementia is chronic and develops slowly, while delirium is a sudden change over a few hours.

The causes of delirium

There are multiple potential underlying causes of delirium. Some of these causes are temporary conditions, and delirium will resolve as the cause does. For instance, some people experience delirium while recovering from surgery or other medical procedures.

Additional causes of delirium include:

People with dementia are more prone to experiencing delirium as a result of the above causes. For example, even a mild infection may cause delirium in someone with dementia. Some people with dementia also experience “sundowning,” or delirium-like behavior that occurs at night.

The causes of dementia

Dementia is a neurodegenerative condition. When a person has dementia, they experience progressive damage and loss of nerve cells in their brain.

When the cells are damaged, they can’t function and communicate properly. This causes the symptoms of dementia.

Often, there’s no specific underlying cause of dementia, although it’s likely genetics and environmental factors play a role. However, some conditions are linked to dementia. These are primarily conditions that cause brain damage and can result in dementia in some cases.

Examples include:

Delirium requires urgent diagnosis and treatment. It can lead to serious complications without treatment. Typically, a person will be evaluated for delirium by looking at their symptoms and their medical history and assessing their current alertness and awareness.

A person will be asked questions to see if they can give information, such as the current year, the months of the year, and their current location. They may also undergo blood and urine testing. If the healthcare team suspects the person has delirium, they will quickly begin to address the underlying cause.

A dementia diagnosis begins with a doctor’s appointment. A doctor will discuss symptoms, medical history, and family history. They’ll do cognitive and neurological assessments to evaluate a person’s current abilities.

In some cases, imaging tests such as MRIs and CT scans might be done. These tests can help doctors get a clear look at the brain so they can see damage to brain cells. This can help confirm a diagnosis. Researchers are also working to develop genetic tests for dementia as well.

Delirium and dementia are conditions that cause similar symptoms. People experiencing either condition can experience confusion, mood changes, paranoia, and hallucinations, and people over 65 are more likely than younger people to experience these conditions.

However, these conditions aren’t the same. Delirium is a change to a person’s normal state that comes on quickly. It’s typically the result of an underlying condition, such as an infection or recent surgery. It requires immediate treatment and can indicate a life threatening condition.

Dementia is a chronic progressive condition that develops slowly over time. Your doctor can work with you on a dementia diagnosis and get you started on a treatment plan.