Mild Cognitive Impairment (MCI): What to Know

Medically Reviewed By Susan W. Lee, DO

Mild cognitive impairment (MCI) is a subtle decline in memory or the ability to think clearly. MCI may be noticeable, but it is not severe enough to interfere with daily routines. People with mild cognitive impairment may be more likely to develop dementia and Alzheimer’s disease than people without, though they do not always develop it. Dementia is a cognitive decline or impairment that interferes with the ability to perform everyday tasks.

Keep reading to learn more about MCI, including its signs, diagnostic techniques, and treatment options.

What is mild cognitive impairment?

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Mild cognitive impairment (MCI) occurs when problems with thought processes occur. Its symptoms may not interfere with daily life but may be noticeable to a person and those around them. They may include:

In older adults

Mild cognitive impairment is common in older adults. Some researchers suggest that 10–20% of people older than 65 have MCI.

With age, other conditions such as stroke, dementia, delirium, brain tumors, chronic alcohol use or misuse, substance misuse, vitamin deficiencies, and some chronic diseases may cause cognitive impairment. Head injury and infection of the brain or the covering of the brain and spinal cord (meninges) can cause cognitive impairment at any age.

In some cases, cognitive impairment may be reversible if the underlying cause is identified and treated. 

Seek immediate medical care (call 911) for the sudden onset of cognitive impairment, especially if it’s accompanied by a high fever (higher than 101°F), neck stiffness or rigidity, rash, head injury, changes in the level of consciousness or alertness, flushing or dry skin, severe nausea and vomiting, fruity breath, or other symptoms that cause you concern. 

Seek prompt medical care for new onset of cognitive impairment or if the existing impairment worsens.

What causes mild cognitive impairment?

Experts are unsure what causes MCI. In some instances of mild cognitive impairment, a person will later develop Alzheimer’s or another condition, such as dementia.

Age can also increase a person’s risk for developing MCI, alongside factors such as:

However, the symptoms of dementia can also occur due to various other factors, which include:

What other symptoms might occur with mild cognitive impairment?

Cognitive impairment may accompany other symptoms, which vary depending on the underlying disease, disorder, or condition. Symptoms frequently affecting the brain may also involve other body systems or disorders.

Other symptoms of dementia

Symptoms of dementia affecting people with MCI include losing things often and forgetting important events.

Symptoms of dementia that do not affect people with MCI include:

  • difficulty having a conversation
  • difficulty reading or writing
  • finding basic activities challenging
  • having difficulty paying bills or handling money
  • getting lost in familiar places
  • having hallucinations, delusions, and paranoia

Infection symptoms that may occur along with cognitive impairment

Cognitive impairment may accompany symptoms related to infection, including Trusted Source Centers for Disease Control and Prevention (CDC) Governmental authority Go to source :

Metabolic symptoms that may occur along with cognitive impairment

Cognitive impairment may accompany other symptoms related to metabolic disordersincluding:

Other symptoms that may occur along with cognitive impairment

Cognitive impairment may accompany symptoms related to other problems, such as injury, stroke, or dementia. These symptoms may include:

  • change in sleep patterns
  • changes in mood, personality, or behavior
  • confusion or loss of consciousness for even a brief moment
  • difficulty with memory, thinking, talking, comprehension, writing, or reading
  • impaired balance and coordination
  • loss of vision or changes in vision
  • nausea with or without vomiting
  • numbness, weakness, or paralysis
  • seizure
  • severe headache

When to seek emergency care

In some cases, cognitive impairment may be a symptom of a life threatening condition. Seek immediate medical care (call 911) if you or someone you are with has any of these life threatening symptoms:

  • change in the level of consciousness or alertness, such as passing out or unresponsiveness
  • change in mental status or sudden behavior change such as confusion, delirium, lethargy, hallucinations, or delusions
  • garbled or slurred speech or inability to speak
  • high fever (higher than 101° F)
  • high-pitched, shrill cries in an infant or small child
  • paralysis or inability to move a body part
  • poor feeding, unusual sleepiness
  • seizure
  • stiff or rigid neck
  • sudden change in vision, loss of vision, or eye pain
  • trauma to the head
  • extreme headache

How is cognitive impairment diagnosed?

A doctor may order tests to determine the underlying cause of the mild cognitive impairment, or they may monitor the symptoms over time. They may ask you to come back every 6–12 months.

Questions for diagnosing the cause of cognitive impairment

To diagnose your condition, your doctor or licensed healthcare practitioner will ask several questions related to your cognitive impairment, including:

  • When did you first notice symptoms of cognitive impairment?
  • What specific symptoms have you noticed?
  • Did anything, such as an injury or illness, precede the symptoms?
  • Were there any prenatal complications or complications of birth?
  • Do you have any other medical conditions?
  • What medications are you taking? Are you taking any new medications?
  • Have you taken any illegal drugs?
  • Do you drink alcohol?

What are the potential complications of cognitive impairment?

Because cognitive impairment can be due to serious diseases, not seeking treatment can result in serious complications and permanent damage. This can include permanent neurological damage or physiological damage if the cognitive impairment is the result of a factor other than Alzheimer’s or dementia.

Once the underlying cause is diagnosed, follow your healthcare professional’s treatment plan to reduce the risk of potential complications.


Mild cognitive impairment (MCI) causes problems with memory or thoughts. These problems may be noticeable to the person experiencing them and sometimes to those around them. However, it will not affect the person’s ability to care for themselves or their daily tasks.

Was this helpful?
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  8. Wang, X., et al., (2021). The association of metabolic syndrome and cognitive impairment in Jidong of China: A cross-sectional study.
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  10. What is mild cognitive impairment? (n.d.).
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Medical Reviewer: Susan W. Lee, DO
Last Review Date: 2022 Oct 28
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