Many people with dementia do not know they have it, and this isn’t stubbornness or denial. It’s a neurological symptom called anosognosia, a physical inability to recognize your own cognitive decline. Estimates suggest that up to 80% of people at the dementia stage experience some degree of this lost self-awareness. So if you’re worried enough to search this question, that worry itself is actually meaningful information.
Why Worrying May Be a Good Sign
This sounds counterintuitive, but the ability to notice and worry about your own memory problems requires the very brain functions that dementia damages. The frontal and parietal lobes handle self-monitoring and self-awareness, and as dementia progresses, these regions deteriorate. The result is that the person losing cognitive ability is often the last one in the room to realize it.
Researchers use the term “subjective cognitive decline” to describe people who notice their own thinking getting worse, even when standard tests still come back normal. A meta-analysis of long-term studies found that only about 14% of people in this category eventually developed dementia, while 27% progressed to mild cognitive impairment. The majority never declined at all. Their memory worries turned out to be normal aging, stress, poor sleep, or anxiety doing what anxiety does best: convincing you something is wrong.
That said, subjective cognitive decline isn’t meaningless. In people who do eventually receive a dementia diagnosis, noticeable memory concerns tend to appear roughly 10 years before the diagnosis. And individuals with early biological signs of Alzheimer’s disease who also report feeling cognitively different have a 40 to 62% chance of progressing to mild cognitive impairment or dementia within three years. The pattern matters more than any single moment of forgetfulness.
Normal Aging vs. Early Dementia
Everyone’s memory gets less sharp with age. The distinction isn’t whether you forget things. It’s what you forget and whether it disrupts your life. Normal age-related changes include misplacing your keys, struggling to find a word but remembering it later, blanking on an acquaintance’s name, or losing track of recent events. These are frustrating, but your overall ability to function stays intact. You still draw on decades of knowledge, recall old memories, and communicate clearly.
The warning signs of dementia look different:
- Getting lost in a familiar neighborhood, not just taking a wrong turn but genuinely not recognizing where you are
- Using strange substitutes for common words, like calling a watch a “hand clock” because the real word is gone
- Forgetting close family members’ names, not a distant cousin’s, but your daughter’s or your spouse’s
- Losing old, well-established memories, not just recent events
- Struggling to complete familiar tasks you’ve done hundreds of times, like paying a bill or following a recipe you know by heart
Problems with judgment, reasoning, depth perception, and attention also show up early in some forms of dementia. If someone is making uncharacteristically poor financial decisions, misjudging distances while driving, or can’t follow a conversation, those are more concerning than occasionally forgetting where they parked.
How Self-Awareness Differs by Type
Not all dementia affects self-awareness in the same way. In Alzheimer’s disease, people often retain a reasonably accurate sense of their own personality early on, even as memory falters. They may notice they’re forgetting things and feel frustrated or frightened by it. As the disease advances, that awareness fades.
Frontotemporal dementia (FTD) is a different story. Loss of insight is actually a core diagnostic feature. People with FTD often undergo dramatic personality shifts, becoming impulsive, socially inappropriate, or emotionally flat, yet they see nothing different about themselves. Research comparing the two conditions found that people with FTD misjudged their own personality across far more dimensions than those with Alzheimer’s. In both cases, patients’ self-descriptions tended to match who they were before the disease, as if their internal self-image simply stopped updating.
This distinction matters practically. A person with early Alzheimer’s might come to you and say, “Something’s wrong with my memory.” A person with FTD is more likely to be brought in by a spouse or coworker who has noticed alarming behavioral changes the person themselves cannot see.
Conditions That Mimic Dementia
Before assuming the worst, it’s worth knowing that several treatable conditions produce symptoms nearly identical to dementia. Depression is one of the most common, sometimes called “pseudodementia” because it can cause such severe problems with concentration, memory, and motivation that it looks like cognitive decline. Once the depression is treated, the cognitive symptoms often resolve.
Other reversible causes include vitamin B12 deficiency, thyroid problems (particularly an underactive thyroid), medication side effects (especially drugs with anticholinergic properties, which include some allergy medications, bladder drugs, and older antidepressants), alcohol use, and infections. Less common but still treatable causes include normal pressure hydrocephalus (a buildup of fluid in the brain that also causes walking problems and bladder issues), brain tumors, chronic subdural hematomas from a head injury, and infections like neurosyphilis or Lyme disease.
The American Academy of Neurology recommends that any evaluation for dementia include brain imaging, screening for depression, a vitamin B12 level check, and thyroid testing. These are standard first steps because ruling out fixable problems is just as important as identifying irreversible ones.
What a Cognitive Evaluation Looks Like
If you or someone you care about is concerned, the first step is a structured cognitive screening. These are short, office-based tests that a primary care doctor can administer. The most widely used is the Montreal Cognitive Assessment, or MoCA, a 30-point test that takes about 10 minutes. It checks memory, attention, language, visual-spatial skills, and executive function. Scores at or below 25 out of 30 generally suggest some degree of cognitive impairment, though the optimal cutoff varies by racial and ethnic background, with research showing that a score of 22 or below is a more accurate threshold for Black participants.
No single screening test diagnoses dementia. A low score triggers more detailed neuropsychological testing, blood work, and often brain imaging. A normal score doesn’t guarantee everything is fine, but it’s reassuring. Other quick screening options include the Mini-Cog, which involves remembering three words, drawing a clock face, and recalling those words, and the Saint Louis University Mental Status Exam (SLUMS), which is free, available online, and tests abilities particularly relevant to daily life, like remembering details from a short story.
What Family Members Should Watch For
Because dementia so often erases a person’s ability to see their own decline, family and close friends play an outsized role in early detection. The practical consequences of anosognosia go beyond simple unawareness. People who don’t believe anything is wrong are less likely to take medications, more likely to put themselves in dangerous situations (like driving when they shouldn’t), and less willing to accept help or use compensatory strategies like reminders and lists.
If you’re worried about someone else, pay attention to changes from their baseline, not compared to other people their age, but compared to how they used to be. A lifelong absentminded person misplacing their glasses is different from a highly organized person who suddenly can’t manage their calendar. Personality shifts, repeated questions within the same conversation, trouble managing finances they previously handled with ease, and withdrawal from hobbies or social activities are all patterns worth noting. Write down specific examples with dates. That kind of concrete information is far more useful to a doctor than a vague report that someone “seems off.”