Delirium vs Dementia: Types and Symptoms of Each

Do you have a loved one suffering from delirium or dementia? It’s important to know the differences, causes, and symptoms of these two conditions so you’re prepared to take care of your loved one. If you are researching the differences between delirium vs. dementia, we have compiled a list of the symptoms and signs you need to be familiar with.

What Are the Differences Between Delirium and Dementia?

Delirium and dementia are both conditions that affect cognitive function, but they differ in their onset, duration, and underlying causes. The differences between delirium and dementia are the following:

1. Onset of Symptoms

One difference between delirium and dementia is the onset of symptoms. Delirium is known as an acute confusional state. The condition occurs when someone experiences an abrupt change in their ability to remember things. On the other hand, dementia progresses slowly over a more extended time period. It is important to seek medical attention if your loved one is experiencing abrupt symptoms of delirium.

2. Risk Factors

If you are comparing the differences between delirium and dementia, delirium can be caused by conditions such as pneumonia, drug use or withdrawal, and dehydration. Mixing prescription medications can cause delirium as well. Some common risk factors for delirium include old age, severe medical conditions, and the use of certain medications. Dementia usually is caused by health conditions such as Alzheimer’s disease—which is a specific type of dementia. Other types of dementia include vascular dementia, lewy body dementia, and frontotemporal dementia. Some common risk factors for dementia include aging, family history of memory issues, and underlying health conditions.

3. Longevity

Delirium is generally a temporary condition that improves over time—if treated properly. It can last anywhere from a couple of days to a couple of months. Whereas dementia is an incurable, long-term condition that worsens over time.

4. Communication Skills

One of the more difficult giveaways of delirium vs dementia is through communication. Delirium can significantly affect one’s ability to communicate clearly with others. People with dementia also often struggle with finding the right words and expressing themselves.

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5. Memory & Concentration Skills

If you are analyzing the distinctive characteristics of delirium vs dementia, it’s important to know that individuals with delirium have functioning memory but deteriorating alertness. However, people with dementia have higher alertness but impaired memory.

6. Responsiveness & Activity

A person with delirium experiences either a significant increase or decrease in activity level. On the other hand, activity levels in people with dementia are typically normal until later stages.

Alzheimer's Disease Stages

3 Types of Delirium

1. Hyperactive

Hyperactive delirium occurs when an individual experiences a significant increase in daily activity levels. This type of delirium is characterized by restlessness, agitation, mood changes, hallucinations, and a rejection of care from family members, friends, and healthcare professionals.

2. Hypoactive

Hypoactive delirium occurs when an individual experiences a significant decrease in daily activity levels. This type of delirium is characterized by lethargy, sluggishness, drowsiness, and dazed behavior.

3. Mixed

A person with mixed delirium transitions between temporary phases of hyperactive and hypoactive delirium. This type is characterized by the symptoms listed above, but the individual switches back and forth between them.

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Dementia Types & Symptoms

Dementia is broken up into two categories: Alzheimer’s type and non-Alzheimer’s type.

1. Alzheimer’s

Dementia in the Alzheimer type category typically presents itself through memory loss, difficulties with language, and loss of normal brain function.

2. Non-Alzheimer’s

Dementia in the non-Alzheimer type category is typically associated with speech impairment, loss of executive function, and noticeable behavior and/or personality changes.

Symptoms Of Delirium

  • Inability to recognize surroundings
  • Cognitive impairment
  • Changes in behavior
  • Emotional disturbance

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If you are analyzing the distinct symptoms of dementia vs delirium, it’s important to be aware that an individual can suffer from both conditions at the same time. People with dementia often develop delirium, but people who experience delirium don’t necessarily have dementia. Since no case is the same, it’s important for every person living with delirium and dementia to receive compassionate, customized care.

Early-Stage Symptoms of Dementia

Symptoms of early onset dementia include:

  • Forgetting recent information
  • Repeating oneself within a short time period
  • Misplacing everyday items
  • Not knowing the date/time
  • Struggling with words
  • Changes in mood, behavior, or interests

Late-Stage Symptoms 0f Dementia

  • Inability to remember things and make basic decisions
  • Increased struggle with words
  • Struggle with daily tasks
  • Decrease in rationality and problem solving
  • Changes in sleeping patterns
  • Frequent negative moods
  • Hallucinations

Terra Vista Community

Trusted Dementia Care Services at Terra Vista

Terra Vista is a dementia care assisted living facility and community in Oakbrook Terrace, IL that is dedicated to fostering the physical and mental health of your loved ones with dementia.

The staff at our community offers innovative memory care services and is committed to providing high-quality, innovative, and personalized care for every resident with dementia who lives in the community. We treat your family like our family. To discuss the advantages of signing up for our Alzheimer’s care assisted living facility and community, give our team a call by phone at 630-793-0753.

Natalie Pic

Meet the Author


Natalie has compiled over eighteen years experience providing outstanding care to people with Alzheimer’s disease and dementia. In addition to being a certified Alzheimer’s and dementia care trainer, McFarland is a licensed continued education instructor for nurses and social workers through the Illinois Department of Professional Regulations. She has also developed several Alzheimer’s research partnerships. Included in those projects were Dr. Virginia Cruz, Ph.D., RN, Associate Professor of SIUE and Dr. George Grossberg, M.D., Medical Director of the Department of Psychiatry and Neurology at Saint Louis University. Natalie is a graduate of Southern Illinois University.