Merck Manual

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Some Causes and Features of Memory Loss

Some Causes and Features of Memory Loss

Cause

Common Features*

Tests

Age-related memory changes (age-associated memory impairment)

Occasional forgetfulness of such things as names or the location of car keys

No effect on thinking, other mental functions, or the ability to do daily activities

A doctor's examination (particularly a neurologic examination and mental status testing to assess functions such as attention, orientation, and memory)

Mild cognitive impairment

Memory loss that is more severe than expected for a person's age, particularly difficulty remembering recent events and conversations (short-term memory loss)

No effect on the ability to do daily activities

An increased risk of developing dementia

A doctor's examination

Sometimes formal neuropsychologic testing, which resembles mental status testing but evaluates function in more detail

Memory loss that becomes worse as time passes, eventually with no awareness of the loss

Difficulty using and understanding language, doing usual manual tasks, thinking, and planning (for example, planning and shopping for meals), resulting in not being able to function normally

Disorientation (for example, not knowing the time or location)

Difficulty recognizing faces or common objects

Changes in personality or behavior (for example, becoming irritable, agitated, paranoid, inflexible, or disruptive)

A doctor’s examination

Usually MRI or CT of the brain

Sometimes formal neuropsychologic testing

Possibly a spinal tap (lumbar puncture) to measure levels of two abnormal proteins (amyloid and tau) that occur in Alzheimer disease

Sometimes blood tests to check for certain causes, such as an underactive thyroid gland (hypothyroidism) or a vitamin deficiency

Memory loss and awareness of the loss, usually accompanied by intense sadness, and lack of interest in usual pleasures

Sometimes sleep problems (too little or too much), loss of appetite, and slowing of thinking, speech, and general activity

Common among people with dementia, mild cognitive impairment, or age-related changes in memory

A doctor’s examination

Sometimes use of standardized questionnaires to identify depression

Drugs, such as

  • Drugs with anticholinergic effects, including some antidepressants and many antihistamines (used in OTC sleep aids, cold remedies, and allergy drugs)

  • Opioids

  • Drugs that help people sleep (sedatives)

Use of a drug that can cause memory loss

Often recent use of a new drug, an increase in a drug’s dose, or a change in health that prevents the drug from being processed and eliminated from the body normally, as can occur in kidney or liver disorders

Typically stopping the drug to see whether memory improves

*Features include symptoms and results of the doctor's examination. Features mentioned are typical but not always present.

CT = computed tomography; MRI = magnetic resonance imaging; OTC = over-the-counter.