Understanding Cognitive Decline: How Your Brain Changes as You Age

Cognitive decline is a regular part of aging. Learn how doctors use the SAGE tool to track it and if there's anything you can do to delay it.

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As you age, you may experience a gradual loss of some thinking abilities. A significant change may indicate another health condition.

Your mind is central to your identity. The sharpness of your thinking, your ability to communicate and connect with others, and the rich trove of memories you’ve collected over a lifetime all have enormous value.

As you get older, you may notice changes in some of your thinking skills, including cognitive decline.

This article explores how your cognitive abilities can change later in life. It also provides some practical guidance to help you keep your brain healthy as you age.

What is cognitive decline?

Cognitive decline is the gradual loss of thinking abilities such as:

  • learning
  • remembering
  • paying attention
  • reasoning

For some people Opens in a new window, a small amount of cognitive decline occurs with age. But more significant changes can be a sign of a cognitive disorder. Injury, illness, and health habits can influence how much and how fast your cognitive abilities change over time.

What are the signs of cognitive decline?

Cognitive decline looks different from person to person. That may be because people vary in their health profiles, life circumstances, and capabilities. Still, some patterns have emerged from the research.

People with mild cognitive decline might:

  • have trouble finding the right words to express themselves, especially when compared with others of the same age
  • lose or misplace things
  • forget appointments and scheduled events
  • become overwhelmed by complex tasks and projects

Keep in mind that typical forgetfulness is not the same Opens in a new window as cognitive decline. It’s not helpful to assume that regular forgetfulness is necessarily a sign of cognitive decline. Such worrying can affect your well-being.

When to see a doctor

If you notice any of these signs, it may be time to visit a healthcare professional:

  • You get lost in once-familiar areas.
  • You become frustrated with communication difficulties.
  • You experience mood or personality changes, such as more anxiety or aggression.
  • You ask the same questions over and over.
  • You have trouble recognizing friends and family members.

How do doctors detect cognitive decline?

A doctor can help you determine whether you’re experiencing typical signs of aging or symptoms of cognitive decline. They may assign you a brief self-screening test to check for symptoms of cognitive decline.

Self-Administered Gerocognitive Examination (SAGE) and other screening tests

There are several screen tests that you can use to check for signs of cognitive decline. These tests usually take about 3 to 15 minutes. They include:

  • Self-Administered Gerocognitive Examination (SAGE)
  • AD8 Dementia Screening Interview
  • Quick Dementia Rating System (QDRS)
  • Saint Louis University Mental Status (SLUMS) test
  • Mini-Cog

SAGE is one of the most common screening tests. You can download the test online Opens in a new window and complete it at home. You can also take it to a doctor’s office to complete.

SAGE differs from the other tests in that it is slightly more complex. A 2022 study Opens in a new window found that SAGE detected cognitive decline in people with MCI 6 months sooner than MMSE, another common test. According to a 2021 review Opens in a new window, SAGE produces a correct result 79% of the time.

Note that these quick tests are not enough to diagnose cognitive decline or dementia on their own. If your score shows some decline, it may be a sign for a doctor to do a more thorough evaluation.

Neuropsychological tests

In an evaluation, doctors often use neuropsychological tests to see whether your thinking and memory skills are changing. Some of the most common tests are:

  • Mini-Mental State Examination (MMSE)
  • Montreal Cognitive Assessment (MoCA)
  • Sahlgrenska Academy Self-Reposed Cognitive Impairment Questionnaire (SASCI-Q)
  • Subjective Cognitive Decline Questionnaire (SCD-Q)
  • Memory Complaint Questionnaire (MCQ)
  • Everyday Cognition (ECog)
  • Clinical Dementia Rating (CDR) Scale
  • 6-Item Cognitive Impairment Test (6-CIT)
  • Hong Kong Brief Cognitive Test (HKBC)

Some of these tests are relatively new. More research is needed to understand how well they predict or measure cognitive decline.

Other tests

A doctor might order a blood test to see if something else — like hypothyroidism or a B12 deficiency — may be causing a change in your thinking abilities.

Brain imaging, such as magnetic resonance imaging (MRI), may help a doctor determine whether something like a stroke or brain tumor is at the root of your symptoms.

Experimental tests

Researchers are also looking into blood or spinal fluid tests Opens in a new window that search for proteins linked to Alzheimer’s disease. These proteins are called beta-amyloid and tau.

In studies, brain imaging Opens in a new window like MRI and PET scans can show changes in some parts of the brain.

The above tests may be able to detect changes in your brain up to 20 years Opens in a new window before symptoms appear. But they’re often too costly, invasive, or complex to use for screening purposes. There’s ongoing research into simpler and more cost-effective screening tests.

What causes cognitive decline?

There are many reasons you may experience age-related changes in thinking and memory. Sometimes, another health condition may be the cause. Examples include:

  • high blood pressure
  • vascular (blood vessel) disease
  • depression
  • sleep deprivation
  • diabetes

Sometimes, a neurological condition such as Alzheimer’s Disease or frontotemporal dementia is the underlying cause.

Your genes and family history also play a role in whether you will experience cognitive decline as you get older. Genes may be responsible for up to 60% to 70% Opens in a new window of the various ways cognition declines due to aging.

At what age does cognitive decline usually start?

Each person is different. Your health behaviors have some influence on your brain function as you age.

A 2020 analysis Opens in a new window of the Health and Retirement Study, which involved around 29,000 participants, found that women first experienced cognitive impairment around age 73. Those women who went on to develop dementia did so at about 83 years old. Men, the study found, experienced cognitive decline near age 70 and dementia at 79 years.

It’s important to know that not everyone with cognitive decline will later have dementia.

The study also found that race and education level affect the age of onset.

For many Black and Latin@ people in the United States, cognitive decline may begin 3 to 6 years Opens in a new window earlier than for white people. Researchers think this disparity could be related to differences in healthcare access and accumulated stress (“weathering Opens in a new window”) over a lifetime.

People with higher education levels Opens in a new window tend to experience cognitive decline at a later age. This may be because they stay mentally active and have more social connections Opens in a new window later in life. They may also have greater access to healthcare and earlier treatment of medical problems.

Are there risk factors linked to faster cognitive decline?

Genes and family history are major risk factors for cognitive decline. But other factors may also lead to a faster or more noticeable decline. These include:

  • diabetes
  • high blood pressure
  • stroke
  • smoking
  • high cholesterol
  • hearing loss

Some of these factors you can control, and some you can’t. Try working with a healthcare team to create a plan to stay healthy — mentally and physically.

Can I prevent or delay cognitive decline?

Some age-related cognitive changes are tied to your genetics. There may not be much you can do to change that risk factor. But there are many other ways to keep your brain healthy and preserve your ability to think.

Here are a few research-supported Opens in a new window steps you can take:

  • Eat a nutritious diet with lots of leafy green vegetables. Studies Opens in a new window suggest that the Mediterranean and DASH diets both slow cognitive decline.
  • Stay physically active.
  • Connect with other people socially.
  • Stimulate your brain with activities, reading, games, and hobbies.
  • Protect yourself from brain injury.
  • Limit the amount of alcohol you drink.
  • Avoid the use of tobacco products.

A 2022 study Opens in a new window suggests that taking a daily multivitamin might help slow cognitive decline. More research is needed to confirm the results.

Frequently asked questions

If you experience cognitive decline, will you develop Alzheimer’s Disease (AD)?

Not necessarily. The National Institute on Aging estimates that just 10% to 20% Opens in a new window of those with MCI later develop AD or related dementia.

Can you reverse cognitive decline?

It depends on what’s causing the changes. If your symptoms are related to an underlying health condition, such as sleep deprivation, treating the cause may reduce your symptoms.

How is depression related to cognitive decline?

It may be a two-way street. Studies Opens in a new window have shown that depression can often precede cognitive decline among older adults. Research Opens in a new window has also shown that people with symptoms of cognitive decline tend to experience depression at a higher rate.

There isn’t yet enough research to suggest a causal link. But researchers do suggest that treating depression might help prevent dementia. Still, more research is needed.

Is there a link between hearing loss and cognitive decline?

Hearing loss is a known risk factor Opens in a new window for cognitive decline. Still, the link isn’t well understood. It may be due to changes in brain structure, reduced social interaction, or increased cognitive effort to understand and process speech.

It’s also a modifiable risk factor. That means treating hearing loss could help slow cognitive decline.

Takeaway

As you get older, you may notice changes in your ability to remember, communicate, and reason. For many people, these changes are mild and are a regular part of aging. For others, forgetfulness, language difficulties, and confusion can disrupt day-to-day living.

If you think cognitive decline may be affecting your mood, personality, or ability to function, a healthcare professional can help you determine whether you’re at risk for more significant brain changes. Self-assessment tests like SAGE can help you and your doctor track your cognition over time.

To keep your brain healthy as you age, eat a healthy diet, exercise regularly, and stay active mentally and physically. You can’t control risk factors like your genetics, but taking good care of your mind and body can make a big difference to healthy aging.

This article originally appeared on Healthline. © 2025 Healthline Media LLC. All rights reserved. Our website services, content, and products are for informational purposes only. Healthline Media does not provide medical advice, diagnosis, or treatment.
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Last updated: November 04, 2024

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By: Healthline

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