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Mild cognitive impairment (MCI)

Medically reviewed by Last updated on Feb 13, 2024.


Mild cognitive impairment (MCI) is the stage between the expected decline in memory and thinking that happens with age and the more serious decline of dementia. MCI may include problems with memory, language or judgment.

People with MCI may be aware that their memory or mental function has "slipped." Family and close friends also may notice changes. But these changes aren't bad enough to impact daily life or affect usual activities.

MCI may increase the risk of dementia caused by Alzheimer's disease or other brain disorders. But some people with mild cognitive impairment might never get worse. And some eventually get better.


The brain, like the rest of the body, changes with age. Many people notice they become more forgetful as they age. It may take longer to think of a word or to recall a person's name.

If concerns with mental function go beyond what's expected, the symptoms may be due to mild cognitive impairment (MCI). MCI may be the cause of changes in thinking if:

If you have MCI, you also may experience:

When to see a doctor

Talk to your health care provider if you or someone close to you notices you're having problems with memory or thinking. This may include trouble recalling recent events or having trouble thinking clearly.


There's no single cause of mild cognitive impairment (MCI), although MCI may be due to early Alzheimer's disease. There's no single outcome for the disorder. Symptoms of MCI may remain stable for years. Or MCI may progress to Alzheimer's disease dementia or another type of dementia. In some cases, MCI may improve over time.

MCI often involves the same types of brain changes seen in Alzheimer's disease or other forms of dementia. In MCI, those changes occur at a lesser degree. Some of these changes have been seen in autopsy studies of people with MCI.

These changes include:

Brain-imaging studies show that the following changes may be associated with MCI:

Changes in brain structure with MCI and Alzheimer's disease

Some changes in brain structure — such as the decrease in size of the brain's memory center (hippocampus) — are typical with aging. However, this reduction in size is greater in those with mild cognitive impairment and even more dramatic in people with Alzheimer's disease.

Brain shrinkage in MCI and Alzheimer's disease

Dementia causes the brain to lose mass, especially in critical areas. Note the difference in size between a healthy brain (top), a mild cognitive impairment brain (middle) and an Alzheimer's disease brain (bottom).

Risk factors

The strongest risk factors for MCI are:

Other medical conditions and lifestyle factors have been linked to an increased risk of changes in thinking, including:


People with MCI have an increased risk — but not a certainty — of developing dementia. Overall, about 1% to 3% of older adults develop dementia every year. Studies suggest that around 10% to 15% of people with MCI go on to develop dementia each year.


Mild cognitive impairment can't be prevented. But research has found some lifestyle factors may lower the risk of getting MCI. Studies show that these steps may help prevent MCI:


No one test can confirm that someone has mild cognitive impairment (MCI). A diagnosis is made based on the information you provide and results of tests that can help clarify the diagnosis.

Many health care providers diagnose MCI based on criteria developed by a panel of international experts:

Neurological exam

As part of a physical exam, a health care provider may perform some basic tests that can reveal how well the brain and nervous system are working. These tests can help detect signs of Parkinson's disease, strokes, tumors or other medical conditions that can impair memory and physical function.

The neurological exam may test:

Lab tests

Blood tests can help rule out physical problems that may affect memory. This can include not enough vitamin B-12 or thyroid hormone.

Brain imaging

An MRI or CT scan can check for a brain tumor, stroke or bleeding.

Mental status testing

Short forms of mental status testing can be done in about 10 minutes. The test will ask to name the date and follow written instructions.

Longer forms of tests can provide details about how someone's mental function compares with others of a similar age and education. These tests also may help identify patterns of change that offer clues about the cause of symptoms.


Mild cognitive impairment is an active area of research. Clinical studies are being conducted to better understand the disorder and find treatments that may improve symptoms or prevent or delay dementia.

Alzheimer's drugs

The Alzheimer's medicine called cholinesterase inhibitors is sometimes given to people with MCI whose main symptom is memory loss. However, cholinesterase inhibitors aren't recommended for routine treatment of MCI. They haven't been found to affect progression to dementia, and they can cause side effects.

The Food and Drug Administration (FDA) has approved lecanemab (Leqembi) for people with Alzheimer's disease and MCI due to Alzheimer's disease. Not all people with MCI are expected to be eligible for the treatment, since only some have MCI due to Alzheimer's disease.

A phase 3 clinical trial found that the medicine slowed cognitive decline in people with early Alzheimer's disease. Lecanemab works by preventing amyloid plaques in the brain from clumping. This study was the largest so far to look at whether clearing clumps of amyloid plaques from the brain can slow the disease.

Lecanemab is given as an IV infusion every two weeks. Side effects of lecanemab include infusion-related reactions such as fever, flu-like symptoms, nausea, vomiting, dizziness, changes in heart rate and shortness of breath.

Also, people taking lecanemab may have swelling in the brain or may get small bleeds in the brain. Rarely, brain swelling can be serious enough to cause seizures and other symptoms. Also in rare instances, bleeding in the brain can cause death. The FDA recommends getting a brain MRI before starting treatment. It also recommends being monitored with brain MRIs during treatment for symptoms of brain swelling or bleeding.

People who carry a certain form of a gene known as APOE e4 appear to have a higher risk of these serious complications. The FDA recommends being tested for this gene before starting treatment with lecanemab.

If you take a blood thinner or have other risk factors for brain bleeding, talk to your health care professional before taking lecanemab. Blood-thinning medicines may increase the risk of bleeds in the brain.

More research is being done on the potential risks of taking lecanemab. Other research is looking at how effective lecanemab may be for people at risk of Alzheimer's disease, including people who have a first-degree relative, such as a parent or sibling, with the disease.

Treating reversible causes of MCI: Stopping certain medicines

Certain medicines can cause side effects that affect thinking. These side effects are thought to go away once the medicine is stopped. Discuss any side effects with your health care provider and never stop taking your medicine unless your provider tells you to do so. These medicines include:

Treating reversible causes of MCI: Other conditions

Other common conditions besides MCI can make you feel forgetful or less mentally sharp than usual. Treating these conditions can help improve your memory and overall mental function. Conditions that can affect memory include:

Lifestyle and home remedies

Study results have been mixed about whether diet, exercise or other healthy lifestyle choices can prevent or reverse cognitive decline. Regardless, these healthy choices promote good overall health and may play a role in good cognitive health.

Alternative medicine

Some supplements — including vitamin E, ginkgo and others — have been suggested to help prevent or delay mild cognitive impairment. However, more research is needed in this area. Talk to your health care provider before taking supplements as they can interact with your current medicines.

Preparing for an appointment

You're likely to start by seeing your primary care provider. If your provider suspects that you have cognitive changes, you may be referred to a specialist. This specialist may be a neurologist, psychiatrist or neuropsychologist.

Because appointments can be brief and there's often a lot to talk about, it's good to be well prepared. Here are some ideas to help you get ready for your appointment and know what to expect from your provider.

What you can do

Questions to ask your doctor

Because time with your health care provider is limited, writing down a list of questions will help you make the most of your appointment. List your questions from most pressing to least important in case time runs out. For cognitive changes, some questions to ask your provider include:

In addition to the questions you've prepared ahead of time, don't hesitate to ask your health care provider to clarify anything you don't understand.

What to expect from your doctor

Your provider also is likely to have questions for you. Being ready to respond may free up time to focus on any points you want to talk about in-depth. Your provider may ask:

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