As we age, our bodies change in various ways. These changes can present both physically and mentally. As we age, our bodies can become more fragile, and things that once were easy can become more challenging. We may notice changes in mobility or balance, and one major area of change many people recognize is cognitive changes.
Our brain ages alongside our body and those changes can affect the way we process information, our memory, and our overall ability to take in information from the world around us. Cognitive decline can also be seen in a range of symptoms from minor to severe. Our memory can change as we age, which is normal to some extent, but if concerns about symptoms go beyond what is typically expected than mild cognitive impairment may be present. Some symptoms of mild cognitive impairment include:
- Forgetting things more often.
- Missing appointments or social events.
- Losing their train of thought. Or not following the plot of a book or movie.
- Trouble following a conversation.
- Trouble finding the right word.
- Finding it hard to make decisions, finish a task, or follow instructions.
- Trouble finding their way around places they know well.
- Poor judgment.
- Changes that are noticed by family and friends.
With a basic knowledge of cognitive decline, you can better understand dementia and delirium and warning signs of them in your senior loved ones. Dementia and delirium may seem similar at first glance, but they are quite different. While dementia is a slow and long-term decline in one's cognitive health and memory, and it’s often progressive, meaning it gets worse over time., delirium is a sudden onset of a short-term change in mental well-being that affects focus and alertness. In today’s blog post, we’ll be further differentiating the two to help you better understand the signs and symptoms and be able to recognize them in your senior loved ones.
What is Dementia?
You may already be familiar with dementia, especially if you have a loved one who has it or perhaps have known someone with it. Some people might associate dementia with a type of cognitive decline, similar to Alzheimer’s.
Dementia is an overarching umbrella term used to describe the symptoms that occur when there's a decline in brain function. There are various types of dementia, with Alzheimer’s being the most common form of dementia, accounting for approximately 60 to 80% of cases.
Dementia is an umbrella term for a group of disorders that impair memory, decision-making, and other cognitive functions. It’s important to note that while cognitive changes are often a normal part of aging, dementia is not considered to be. Some seniors may develop dementia as they get older, and others may not. The way in which the symptoms of dementia can also look different for each person who has it.
Different diseases can cause dementia, so you can’t pinpoint one cause. Many of these diseases are associated with an abnormal build-up of proteins in the brain.
This build-up causes nerve cells to function less effectively and ultimately die. As the nerve cells die, different areas of the brain shrink.
What is Delirium?
You may have heard of the word delirium before, perhaps used in a book to describe someone in a state that is not natural to them, a strange sort of out-of-body experience. The major difference between something like delirium and dementia is the time frame. Similar to the way delirium may be presented in books, it’s often temporary and will eventually go away. Dementia, on the other hand, is a progressive condition and will only worsen with time.
An article from the Alzheimer’s Research Association explains that delirium is a sudden disturbance in thinking and awareness that makes it hard to stay focused, alert, or oriented. It results in confusion, disordered thinking, inattention, and distractibility. A person may have less awareness of their surroundings and may have hallucinations or delusions.
Delirium can occur at any age, but it is more common among older adults and those in hospitals. During their hospital stay, 29–64% of older persons experience delirium. Additionally, it is prevalent among patients in intensive care units, following surgery, and among residents of nursing homes.
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:
- urinary tract infections and other bacterial infections
- pneumonia, the flu, and other viral infections
- insomnia and sleep deprivation
- dehydration
- thyroid dysfunction
- metabolic conditions
- kidney failure
- liver failure or liver disease
- congestive heart failure and other serious heart diseases
- neurological conditions, such as meningitis, head trauma, or a brain tumor
- intoxication
- certain medications, including psychoactive drugs, opioids, and anticholinergics
- withdrawal from substances or medications
An interesting overlap between the two is that people with dementia are often more prone to experiencing delirium as a result of these causes.
A cause of delirium, according to experts, is the degeneration of particular brain cells that cause dementia. So seniors who already have dementia have an increased risk of experiencing delirium. When people with dementia have an illness like an infection, or are recovering from an operation, they are particularly vulnerable to abrupt and severe cognitive and behavioral issues.
In turn, experiencing delirium can also increase the risk of developing dementia as the brain cells are prone to long-term damage following an episode (or recurring episodes) of temporary impairment of brain function.
Dementia vs. Delirium:
While delirium and dementia are common causes of cognitive impairment in older adults, they can be considered distinct but also deeply connected and interrelated. Delirium, an acute confusional state, has been linked to the chronic and progressive loss of cognitive ability seen in dementia. Individuals with dementia are at higher risk for delirium, and delirium itself is a risk factor for incident dementia. Additionally, delirium in individuals with dementia can hasten underlying cognitive decline.
An article on the relationship between delirium and dementia explains that delirium and dementia are the most common causes of cognitive impairment in older adults. Delirium, an acute state of confusion characterized by impairments in attention and cognition, has been linked to the chronic and progressive loss of cognitive ability as seen in dementia. Individuals with dementia are at higher risk for delirium, and delirium itself is a risk factor for incident dementia.
They further state that Delirium is independently associated with a decrease in cognitive measures months after resolution, and there is overwhelming evidence that delirium is an independent predictor of adverse outcomes and faster cognitive decline.
Symptoms:
Several symptoms of dementia and delirium are similar, which can confuse families when they’re trying to decipher which one their loved one may be dealing with. They can also have similar outcomes, such as people falling, getting lost, or getting hurt.
As we mentioned above, delirium also increases the risk of developing dementia & dementia makes one more prone to developing delirium. So both may be present concurrently.
People with delirium experience altered awareness, which mostly impairs their focus. They may struggle to focus, maintain, and shift their attention. Meanwhile, dementia primarily impacts memory.
Dementia Symptoms
Symptoms of dementia can vary significantly from one person to another, but symptoms often include issues with:
- communication
- attention
- memory (forgetfulness)
- visual perception
- judgment, reasoning, and problem-solving
Delirium Symptoms
Delirium symptoms usually appear within a few hours or days. Symptoms can also fluctuate throughout the day, and individuals may experience times without any symptoms.
Additionally, they tend to decrease during the day and worsen at night or in an unfamiliar environment.
Typical symptoms and indicators include:
- Inattention, or trouble focusing, shifting, or retaining attention
- Confusion, or not knowing who they are, where they are, or the time
- Slurred, confused, or rambling speech
- Emotional changes, such as anxiety, irritation, anger, depression, and fear
- Abrupt changes in mood
- Agitation, hostility, or restlessness
- Perceptual abnormalities like illusions or hallucinations
- Being quiet, distant, drowsy, or lethargic
- Disrupted eating and sleeping habits
- Changes in personality
Risk Factors:
Dementia Risk Factors
The most common risk factors for dementia include: being at least 65 years old and having a family history of dementia (siblings or parents). Various other risk factors can increase your risk of developing dementia as a senior, such as activity levels, mental health, diet, and more.
Delirium Risk Factors
Delirium almost always has a specific trigger, something acute or short-term that’s putting stress on the body or brain and is often multifactorial. A person is more likely to have delirium if they have the following risk factors:
- Male
- Over 70 years of age
- Brain conditions such as dementia
- Alcohol intoxication
- Multiple coexisting disorders
- Taking multiple medications
Diagnosis and Treatment/Management:
An article on Differentiating Delirium Versus Dementia in Older Adults explainsthat the DSM-5 (a diagnostic and statistical manual for healthcare providers) requires the following criteria for delirium:
- Disturbance in attention and awareness develops acutely and tends to fluctuate in severity
- At least 1 additional disturbance in cognition
- Disturbances that are not better explained by preexisting dementia
- Evidence of an underlying organic cause or causes
Additionally, the DSM-5 formulated the following criteria to diagnose dementia:
- A significant cognitive decline from the baseline level of performance in 1 or more cognitive domains. This can be based on the concerns of the patient, the caregiver, or the significant informant, or on cognitive performance on neuropsychological testing.
- The cognitive impairment interferes with the activities of daily living.
- The cognitive decline does not occur exclusively in the context of delirium.
- No other medical or psychiatric condition better explains the cognitive decline.
Management of delirium centers on identifying and addressing underlying etiologies, reducing predisposing and precipitating factors, and prioritizing pain management without medications. Dementia management involves both supportive care and medication intervention. Early and accurate differentiation from delirium remains essential for appropriate management and improved outcomes.
There is no cure for dementia, but there are medications that can help with memory and ease other associated symptoms. In order to treat delirium, it’s important to first identify the underlying cause and to help maintain a peaceful environment.
How Senior Industry Services Can Help:
Transitioning from hospital to home can be challenging, for both seniors and their families. This challenging process can be even more burdensome when dementia and/or delirium are added to the mix. Luckily, Senior Industry Services is here to help you! Our website provides resources and information to help you at whatever stage you are at with your senior loved one, whether it be researching senior living options or learning more about the various transitions seniors face, such as leaving the hospital after an injury, illness, or surgery. Our Hospital-to-Home resource is designed to be your guide to a confident and safe transition because coming home from the hospital should bring relief, not confusion. This resource was thoughtfully curated to help families think through what happens after discharge, including questions about home health, home care, rehabilitation, medications, equipment, follow-up appointments, and safety at home.
If you need extra support or have more questions, feel free to reach out, or use our other resource, Senior-AI, which provides a great starting point for families to search through resources and information for senior care and senior living. You can also explore the Central Texas Senior Care Directory when you're ready to find local providers and services. Or just reach out to us if you have more questions or need further assistance! We are here to help make Central Texas the best place for seniors to age!
Written for Senior Industry Services by Lauren Hope Bartling
About Senior Industry Services
Senior Industry Services (SIS) is a Central Texas resource connecting seniors, families, caregivers, healthcare professionals, and local businesses through education, technology, and community collaboration.
SIS provides educational articles, Senior-AI tools, a searchable Senior Resource Directory, local service information, community resources, professional networking events, and educational opportunities.
We explore and educate on topics such as healthy aging, caregiving, senior living, dementia, hospital-to-home transitions, Medicare, Medicaid, Veterans benefits, long-term care planning, and other issues affecting seniors and their families.
Senior Industry Services serves communities across Central Texas, including Austin, Round Rock, Georgetown, Cedar Park, Pflugerville, Lakeway, Buda, Kyle, Bastrop, Dripping Springs, Marble Falls, Burnet, Temple, Belton, Killeen, Harker Heights, Waco, San Marcos, New Braunfels, Canyon Lake, Bryan–College Station, and surrounding areas.
Whether you’re searching for reliable information, exploring local senior services, using Senior-AI, or looking to connect with trusted professionals, SIS is designed to be a central online resource for aging and senior care throughout Central Texas! Explore our website to learn more about all we have to offer to families, seniors, and senior care professionals in Central Texas!
About the Author
Lauren Hope Bartling is a content writer for Senior Industry Services & Oasis Senior Advisors of Austin and Central Texas. She searches and writes educational content focused on healthy aging, caregiving, healthcare, senior living, and community resources. Her goal is to help seniors, families, caregivers, and healthcare professionals better understand the challenges of aging through accurate, practical, and easy-to-understand information that supports informed decision-making.
References:
Adsule P, Mohanaselvan A, Schoo C. Differentiating Delirium Versus Dementia in Older Adults. [Updated 2026 Sep 14]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan-. Available from: https://www.ncbi.nlm.nih.gov/sites/books/NBK570594/
Alzra. (2025, December 11). Dementia vs delirium: Everything you should know. Alzheimer’s Research Association. https://www.alzra.org/blog/dementia-vs-delirium/
Fong, T. G., & Inouye, S. K. (2022). The inter-relationship between delirium and dementia: the importance of delirium prevention. Nature reviews. Neurology, 18(10), 579–596. https://doi.org/10.1038/s41582-022-00698-7
Mayo Foundation for Medical Education and Research. (2024, October 24). Mild cognitive impairment (MCI). Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/mild-cognitive-impairment/symptoms-causes/syc-20354578
NHS. (n.d.). Causes of dementia. NHS choices. https://www.nhs.uk/conditions/dementia/about-dementia/causes/
Srakocic, S. (2023, August 14). Delirium vs. dementia: How to recognize an emergency. Healthline. https://www.healthline.com/health/dementia/delirium-vs-dementia
Umoh, M. E., Fitzgerald, D., Vasunilashorn, S. M., Oh, E. S., & Fong, T. G. (2024). The Relationship between Delirium and Dementia. Seminars in neurology, 44(6), 732–751. https://doi.org/10.1055/s-0044-1791543
What’s the difference between delirium and dementia? Cleveland Clinic. (2026, September 9). https://health.clevelandclinic.org/delirium-vs-dementia