The often overlooked first sign of Alzheimer’s

Early on, mild cognitive impairment can be hard to identify—but it's worth looking out for symptoms.

A pensive older man wonders if his forgetfulness and cognitive impairment are signs of early onset Alzheimer’s disease.

Updated on June 27, 2024.

Alzheimer’s disease is the seventh leading cause of death in the United States. About 120,000 people in the U.S. die of the brain disorder each year. It often begins slowly, sometimes silently, and eventually takes a toll. People in the final stages may become unable to recognize friends and family, speak, or function on their own.

There is no cure for Alzheimer’s or other forms of dementia—an umbrella term for severe decline in memory and mental ability—and experts don’t fully understand what causes them in most cases. Many researchers believe that the groundwork for developing these conditions is laid down years or decades before symptoms begin.

One such issue that may lead to Alzheimer’s disease is called mild cognitive impairment (MCI). Fortunately, you can take steps to help slow the progression of MCI, and perhaps lower the risk of Alzheimer’s. 

But in order to get treatment for MCI, you have to know what it is and how to recognize it. 

What is mild cognitive impairment? 

Like dementia, MCI is an umbrella term. It often, though not always, involves a decline in memory. It can also entail decline in other executive functions such as language and visual-spatial awareness. The condition affects about 1 in 10 people by age 70, according to the Alzheimer’s Association.

“There’s no singular, specific cause [of mild cognitive impairment],” says Bruce Morgenstern, MD, a neurologist in Lone Tree, Colorado. It’s believed that many cases stem from the same kind of brain changes that occur in early stages of Alzheimer's or other forms of dementia. 

MCI is frequently a precursor to more serious memory impairment. In fact, research suggests that each year, up to 15 percent of people with MCI progress to dementia. It’s not inevitable, however. In fact, some cases of MCI never worsen—and some even improve. 

What is "normal" forgetfulness? 

“As we age, our memories are not as good,” says Dr. Morgenstern. We aren't able to remember things as quickly as we get older, for example.

“I tell my patients, ‘You probably can’t run the 100-yard dash in 8 seconds anymore, either, but that’s normal,’" says Morgenstern. "Your memories are there, it just takes longer to find them.”  

“But MCI,” he adds, “where there is true memory lost, is not normal.” 

Morgenstern describes MCI as an absence of memory. If you just asked your spouse what to pick up at the grocery store, but can’t quite remember the full answer, it’s no reason to be alarmed. If you can’t remember that the conversation happened at all, it could be a sign of cognitive impairment.

Recognizing and diagnosing MCI 

While the symptoms of MCI may be significant enough to be detected by the people having them, the condition is often noticed by other observers. 

Morgenstern says there are a few red flags that make him think someone is experiencing more than just the effects of normal aging. These first signs of Alzheimer’s or cognitive impairment may include:

  • Repeating questions 
  • Getting lost while driving in your own neighborhood 
  • Not knowing the date, month, or year 
  • Having difficulty with simple tasks like logging into a computer 

Diagnosing MCI is a multiple-step process. A healthcare provider (HCP) will assess your medical history and responses to questionnaires. You’ll also receive a physical exam, along with thinking and memory tests. Your HCP will have to rule out other conditions, as well. Alcoholism, strokes, brain tumors or masses, vitamin B12 and thyroid deficiencies, and medication side effects can all mimic or lead to MCI or dementia.

"The biggest masquerader is depression,” Morgenstern says.  

Keeping your brain sharp 

While there is no treatment for many issues contributing to MCI or dementia, certain conditions can be improved or even remedied. “Alcoholism, depression, side effects from medication—those are treatable,” says Morgenstern. Speak with a healthcare provider about steps you can take to help address these issues, and how you can proactively attend to other, more controllable risk factors such as smoking, high blood pressure, and low physical activity.

Getting regular exercise, for example, has been repeatedly tied to a lower dementia risk. In one 2022 meta-analysis of more than 250,000 people published in the British Journal of Sports Medicine, researchers found consistent physical activity was “significantly associated” with reduced chances of all-cause dementia and Alzheimer’s disease. The association stood regardless of age, and remained even after 20 years of follow-up studies.

For health benefits, experts recommend 150 minutes per week of moderate physical activity or 75 minutes per week of vigorous physical activity. Time spent exercising should preferably be spread across multiple days.

Scientists believe that cardiovascular health translates into brain health. The Sharecare app (available for iOS and Android) tracks your fitness to help you keep your heart—and, in turn, your brain—in top shape.

Article sources open article sources

Kramarow EA, Tejada-Vera B. Dementia mortality in the United States, 2000–2017. National Vital Statistics Reports; vol 68 no 2. Hyattsville, MD: National Center for Health Statistics. 2019.
Xu JQ, Murphy SL, Kochanek KD, and Arias E. Deaths: Final data for 2019. National Vital Statistics Reports; vol 70 no 08. Hyattsville, MD: National Center for Health Statistics. 2021.
Xu JQ, Murphy SL, Kochanek KD, Arias E. Mortality in the United States, 2021. NCHS Data Brief, no 456. Hyattsville, MD: National Center for Health Statistics. 2022.
Alzheimer’s Association. What Is Dementia? Accessed June 21, 2023.
National Institute on Aging. What Causes Alzheimer's Disease? Content reviewed December 24, 2019.
Alzheimer’s Association. More Than Normal Aging: Understanding Mild Cognitive Impairment. 2022.
Alzheimer’s Association. Mild Cognitive Impairment (MCI). Accessed June 21, 2023.
UCSF Weill Institute for Neurosciences. Executive Functions. Accessed June 21, 2023.
Iso-Markku P, Kujala UM, Knittle K, et al. Physical activity as a protective factor for dementia and Alzheimer’s disease: systematic review, meta-analysis and quality assessment of cohort and case–control studies. British Journal of Sports Medicine 2022;56:701-709.
Alzheimer’s Society (UK). Physical exercise and dementia. Accessed June 21, 2023.

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