15 Warning Signs of Dementia You Shouldn’t Ignore

Symptoms can vary widely from person to person. Here are some telltale indicators

Rachel Nania,

Updated August 012025

AARP

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En español

Published November 202024

/ Updated August 012025

illustration of woman sitting in armchair looking out window

Jon Krause

You’re running late because you can’t find your keys. Of coursethey’re buried in your bag.

You walk into the living room to retrieve something important. What was it again?

An acquaintance greets you in the grocery store. Her name escapes you.

Moments of forgetfulness can happen at any ageand according to the National Institute on Aging (NIA)may happen even more as you age. Stillmemory lapses can provoke anxiety for older adults who are often left wondering whether it’s all normal or a sign of something more serious.

“It’s important for people not to be too upset at every little cognitive change,” says John DicksonM.D.a neurologist at Massachusetts General Hospital in Boston.

Stillresearch suggests many are. Results from a 2019 National Poll on Healthy Aging found that nearly half of respondents ages 50 to 64 are worried about developing dementia. Similarlya 2021 survey from AARP found that nearly half of adults 40 and older think it’s likely they will get dementia. In realityabout 1 in 9 Americans 65 and older has dementiaaccording to the Centers for Disease Control and Prevention.

While dementia is not inevitableit is important to know the warning signs so that you or a loved one can get evaluated if there are concernsDickson says.

Here’s what to look out for.

What is dementia?

Dementia is an umbrella term for a decline in mental ability that interferes with daily life. It can diminish focusattentionlanguage skillsproblem solving and visual perception. Dementia can also make it difficult for a person to control emotions and can even lead to personality changes. More than 55 million people worldwide have dementiaaccording to the World Health Organization.

15 warning signs of dementia

1. Short-term memory loss. It’s one thing to forget the name of the actor who starred in the movie you went to see with friends yesterday. It’s another to forget you went to see a movie with friends yesterday. “Those more significant lapses” — especially when it comes to recent events — are concerningsays Judith HeidebrinkM.D.a neurologist and clinical professor at University of Michigan Health.

Short-term memory loss can be a common symptom of Alzheimer’s diseasethe most common type of dementiaDickson says. “That’s because the short-term memory-forming center of the braincalled the hippocampusis affected early in the disease process.”

2. Word loss. We’ve all experienced a time or two when your brain can’t find the right wordeven though it’s on the tip-of-the-tongue. That can be normalsays Heather WhitsonM.D.a professor of medicine at Duke University School of Medicine and director of the Duke Center for the Study of Aging and Human Development. But if it’s happening a lot and you find that a person is substituting in words that don’t fit the conversationthat’s worrying.

For exampleWhitson saysa person might want to ask“Have you seen my jacket?” But when they can’t find the word for jacketthey ask“Have you seen my shirt?”

Another warning sign is difficulty joiningfollowing or completing conversations. “Those types of communication skills can be an early symptom,” Heidebrink says.

3. Difficulty multitasking. If you’re someone who has always put out a Thanksgiving dinner without a hitchand suddenly you find that staple side dishes are missing from the spreadthe rolls are burned and dinner is delayed by two hoursthat could signal something more serious is at play. “If it just doesn't seem like it's happening wellor it's happening with a lot more effortthat would be a sign that there are executive function issues,” Whitson says.

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4. Repetition. “If a person is being told by family or friends that they are repeating questions or repeating stories and statements in a short timeframewithout seeming to realize that they just told the person thator they just asked that same question and it was answeredthat's a red flag,” Whitson says.

5. Personality changes. A sudden and routine loss of interest in familyfriendswork and social events can be a warning sign of dementia. “People may feel less comfortable in social situations — holding a conversationremembering the conversation — so they may start to withdraw from social situations,” Heidebrink says.

A 2023 study published in the Journal of Alzheimer’s Disease found that apathy may be a sign that someone is progressing from mild cognitive impairment (MCI) — symptoms of memory loss or thinking problems that are not as severe as dementia — to Alzheimer’s disease. Acting increasingly anxiousconfusedfearful or suspicious may also be a sign of dementiaaccording to the Alzheimer’s Association.

6. New sleep behaviors. While Whitson says sleep issues can be “very common” among older adultssome sleep behaviorssuch as sleepwalkingare not a normal part of aging. “It's important to know that there are some types of dementia that are associated with altered sleep behavior — acting out dreams or talking in your sleepwhen that wasn't something that the person used to do,” Whitson says.

7. Worsening sense of direction. Changes in sense of direction can also occur with dementiaDickson saysand this can manifest in things like difficulty driving and getting lost in familiar environments.

“Sometimes it's just a loss of confidence,” Heidebrink adds. “People will start to restrict their driving to very familiarclose destinationssort of low-speedlow-traffic situationsor good weather only.”

8. Depression. A new and sudden onset of depression later in life can be a warning sign of dementiaDickson says. According to the Alzheimer’s Associationup to 40 percent of people with Alzheimer’s disease suffer from significant depression.

Depression may not just be a symptom of dementia but also a potential precursor. A 2023 study published in JAMA Neurology found that dementia risk more than doubled for adults previously diagnosed with depression.

9. Confusion about time and place. If someone forgets where they areor can’t remember how they got therethat’s a red flag. Another worrisome sign is disorientation about time — for exampleroutinely forgetting what day of the week it issays Jason KarlawishM.D.a neurologist and professor of medicine at the University of Pennsylvania Perelman School of Medicine and codirector of the Penn Memory Center.

10. Difficulty with visual or perceptual tasks. Tripping over something because you don’t recognize that it’s in the wayor not being able to make sense of the time on a clock could be warning signs of dementiaHeidebrink says. Difficulty with balancetrouble reading and problems judging distance or distinguishing color and contrast can also be early indicatorsthe Alzheimer’s Association says.

11. Financial missteps. Money problems may be one of the first noticeable signs of Alzheimer’s disease and related dementiasaccording to the NIA.

“There's a lot of reasoning and memory that go into financial tasksand so [money management errors] can certainly be an early way that people experience changes,” Heidebrink says.

According to the NIAsigns of money problems can include difficulties with the following:

Counting change
Paying for a purchase
Calculating a tip
Balancing a checkbook
Understanding a bank statement

12. Changes in judgment. People with dementia may experience changes in judgment and decision making that can affect everything from their appearance to their financial wellbeingthe Alzheimer’s Association says.

A recent study led by researchers at the University of Southern California looked at brain images from 97 adults over the age of 50 and found that people who had brain changes associated with early stages of Alzheimer’s were more vulnerable to financial scams. While not a singledefinitive indicator“assessing financial vulnerability in older adults could help identify those who are in the early stages of mild cognitive impairment or dementiaincluding Alzheimer’s disease,” researcher Duke Han said in a news release.

13. Misplacing things. We all lose our keysreading glassesthat important piece of mail you meant to hold onto. But putting things in unusual placesor misplacing something and not being able to retrace your stepscan be an early warning sign of dementiaaccording to the Alzheimer’s Association.

It’s easy to lose track of thingsespecially when adjusting to a new routinelike retirementWhitson says. What’s more concerning is if you find what you’re looking forbut have no recollection of putting it there in the first place.

“If you’re frequently finding that you just have no memory of being in that room with that [missing object]to methat is more alarmingbecause that suggests that something with short-term memory is not registering,” Whitson says.

14. Misusing items. Another subtle symptom “is not using things for their correct and intended purpose,” Whitson says. For exampleeating with a spoon when you would usually select a forkor pouring wine into a beer glass.

15. Hallucinations. Delusions or hallucinations can be a symptom of dementia — “particularly visual hallucinationslike seeing people or animals that aren't there,” Dickson says.

Most common types of dementia

These conditions are the leading causes of dementia. People can also have mixed dementiaa combination of two or more typessuch as Alzheimer’s and vascular dementia.

Alzheimer’s disease. Alzheimer’s is characterized by amyloid plaques and tangled fibers in the brain and by a loss of connections between nerve cells. Damage initially appears in the hippocampusan area of the brain involved in memory formationand gradually spreads. An estimated 7.2 million Americans age 65 and older are living with Alzheimer’s diseaseaccording to a 2025 report from the Alzheimer’s Association. By 2050this number is expected to rise to 13 millionthe same report states.

Vascular dementia. The second most common type of dementia results from damage to the vessels that supply blood to the brain. It tends to affect focusorganizationproblem-solving and speed of thinking more noticeably than memory. It’s estimated that 5 to 10 percent of people with dementia have vascular dementia.

Lewy body dementia. Abnormal protein deposits in the braincalled Lewy bodiesinterfere with brain chemistry and lead to problems with behaviormoodmovement and thinking. More than 1 million people in the U.S. have been diagnosed with Lewy body dementiaaccording to federal statistics.

Frontotemporal disorders. Degenerative damage to the brain’s frontal and temporal lobes is the most common cause of dementia in people age 65 and younger. Symptoms might include apathy; difficulty communicatingwalking or working; emotional changes; and impulsive or inappropriate behaviors. According to UCSF Healthfrontotemporal dementia affects an estimated 1 in 5,000 to 10,000 people.

Additional sources: National Institute on AgingMayo Clinic

What to do if you notice symptoms

If you’ve noticed changes or have any concerns related to your thinking and memoryor that of a loved oneit’s important to call a doctor sooner than laterhealth experts say.

8 ailments that can mimic dementia

Any number of treatable conditions can cause dementia-like symptoms. Some of the most common:

Alcohol abuse
Anxietydepression or stress
Blood clotsbrain infections or tumors
Delirium
Head injuries
Kidneyliver or thyroid problems
Side effects of medication
Vitamin deficiencies

Hearing loss can also be mistaken for dementiaWhitson says. “Sometimesif somebody is repeating a questionit might be because they didn't hear the answer before," she explains.

Source: National Institute on Aging

A big reason: “There are many possible causes of these changes,” Heidebrink says. “Not every case where someone is experiencing these changes is automatically Alzheimer's diseasefor example. There could be other causes — a medication side effecta metabolic hormone imbalancesomething else that could be treatable.”

If the changes are due to dementiaan early diagnosis has benefits. For examplethere are newly approved medications that may slow the progression of Alzheimer’s diseaseand research suggests the drugs work better in the beginning stages of the disease. Plusan early diagnosis makes individuals eligible for a wider variety of clinical trialsthe Alzheimer’s Association points out.

You can start with your primary care providerwho may refer you to a specialistlike a neurologist or geriatric psychiatristfor a more thorough evaluation and definitive diagnosis.

How is dementia diagnosed?

Some methods doctors use to help diagnose dementia:

Cognitive and neurological tests assess languagemathmemoryproblem-solving and other types of mental functions.
Blood teststhough relatively new and not yet widely availablecan measure levels of beta-amyloid and p-tau217hallmarks of Alzheimer’s disease.
Brain scans such as MRI or PET imaging can spot changes in brain structure and function. These tests also can identify strokestumors and other problems that can cause dementia.
Mental health evaluations can determine whether a mental health condition is causing or affecting the symptoms.
Genetic tests may be helpful if symptoms appear before age 60. Early-onset Alzheimer’s is strongly linked to geneticsaccording to the Mayo Clinic. Talk with a genetic counselor before and after getting tested.