Mild Cognitive Impairment (MCI): What to Know

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.

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:

• loss of higher reasoning
• forgetfulness
• learning disabilities
• concentration difficulties
• decreased intelligence
• other reductions in mental functions
• changes in mood

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. 

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:

• genetics
• diabetes
• depression
• stroke

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

• sleep apnea
• depression
• vitamin B12 deficiency
• infection
• medication toxicity
• alcohol use
• thyroid disorders
• nutritional deficiencies
• head injuries
• other neurological disorders

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.

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

Cognitive impairment may accompany symptoms related to infection, including:

• fever
• headache
• malaise or lethargy
• muscle twitching, spasms, or seizures
• nausea with or without vomiting
• rash
• stiff or rigid neck

Cognitive impairment may accompany other symptoms related to metabolic disorders, including:

• abdominal pain
• abnormal heart rhythm such as rapid heart rate (tachycardia) or slow heart rate (bradycardia)
• changes in skin
• confusion or loss of consciousness for even a brief moment
• difficulty breathing or rapid breathing
• nausea with or without vomiting
• fatigue
• feeling very thirsty
• frequent urination or decrease in urine output
• fruity breath
• muscle weakness

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

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

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.

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?

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.