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The #1 Sign You Have Dementia, According to a Doctor

It's important to know the common signs.
FACT CHECKED BY Emilia Paluszek

The brain disorder known as dementia is increasingly common: more than 6.5 million Americans have the condition, and that number is expected to rise dramatically in the next few decades, as the over-60 population increases. Alzheimer's disease is the most common form of dementia. Although dementia is a progressive disease that currently has no cure, it's important to be alert to the most common symptoms of dementia, so treatment can pursued if it's appropriate. We asked doctors to tell us about the #1 sign of dementia, along with other common symptoms. Read on to find out more—and to ensure your health and the health of others, don't miss these Sure Signs You've Already Had COVID.


An Inability to Learn

Senior Hispanic Man Suffering With Dementia Trying To Dress

"The key early symptom to detecting Alzheimer's disease is the diminishing of one's learning capacity," says Dr. James Dan, geriatric clinical advisor and member of the Senior Helpers board of directors. "Early Alzheimer's disease patients lose the capacity to learn. They struggle to retain even after being specifically retaught."

This inability is caused by the brain's reduced capcacity to form new memories. That can cause other symptoms as well. "Seeing medical attention should be a priority when there is an inability to learn or relearn a task, trouble with recent memory or memory loss, withdrawal from long, enjoyed social activities, such as family events or game night with friends," says Dan.

Read on to find out more about the most common symptoms of dementia and Alzheimer's.


Short-Term Memory Loss Is Common

older man with dementia talking to doctor
Shutterstock / Robert Kneschke

"The first cognitive function to fail in dementia is short-term memory," says Dr. Robert G. Fawcett, a psychiatrist and author of Calming the Bipolar Storm. "Short-term memory refers to an ability to recall things that you experienced from about three minutes ago through the recent past. Learning new tasks becomes extremely difficult because the brain can't lay down new memory traces."


Signs of Short-Term Memory Loss

Portrait of worried senior man sitting on sofa in living room

According to Fawcett, some of these situations may indicate short-term memory loss:

  • Losing items more often. You many not recall where you put your keys or your glasses.
  • You may not remember if you took your daily medications, unless you have a checklist or pill-minder. 
  • You may forget where you parked your car in the lot, although you still remember the route you took (that's a long-term memory, which is initially preserved in dementia and Alzheimer's). 
  • You can't recall what you had for breakfast hours earlier. 

"This pattern of short-term memory loss is seen in Alzheimer's dementia, in which cells of the hippocampus die off early in its course," says Fawcett. "The hippocampus is very important in laying down new memories."

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How Is This Different From Normal Aging?

Portrait of a worried mature woman having problems with her finances

"It's important to understand we all will experience some cognitive slowing as we age, but normal aging should not impact our ability to function independently, or to learn new information," says Dr. Heather M. Gooden, a physician who treats dementia patients and author of the book Passages. "It may take longer than it used to, but we can continue to learn new things into our second century of life if we choose."


Other Symptoms of Dementia

Senior woman conducting an interview

These are some other common early symptoms of dementia, according to Dr. Gooden:

  • Difficulty with complex tasks, such as managing a checkbook or cooking familiar recipes involving multiple steps. 
  • Getting lost in familiar places or on a familiar route when driving home.
  • Word finding difficulty. This is usually noticed with people who didn't have issues before. (Some people have trouble remembering names at any age, but if it's a new development, it could be a sign of dementia.)
  • Behavior changes. "An under-recognized sign of early dementia, this can include mood changes, an increase in odd behavior, impulsivity, anxiety about change in routine, or sleep disruption beyond what is normal for a person," says Gooden. 

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When to See a Doctor

Senior woman in consultation with her female doctor or therapist

If you or a loved one are experiencing symptoms of dementia, consult your primary care physician, who can take a proper history and physical exam and investigate other potential medical causes. "Many physical and mental illnesses can affect memory and are potentially treatable if found early," says Gooden. "There are also disorders that can mimic early dementia, particularly depression and delirium, and they must be ruled out prior to getting an official diagnosis of dementia."

And to protect your life and the lives of others, don't visit any of these 35 Places You're Most Likely to Catch COVID.

Michael Martin
Michael Martin is a New York City-based writer and editor. Read more about Michael