What is mild cognitive impairment (MCI)?
The short answer
Mild Cognitive Impairment (MCI) is the clinical category between normal aging and dementia. It means measurable cognitive decline beyond what's expected for age, but not severe enough to interfere with daily independent functioning. It is not dementia, but it significantly elevates dementia risk.
The data
| Category | Prevalence (65+) | Annual conversion to dementia |
|---|---|---|
| Cognitively normal | ~65–70% of 65+ | ~1–2%/year |
| Mild Cognitive Impairment (MCI) | ~15–20% of 65+ | ~10–15%/year |
| Dementia | ~10% of 65+ | Established diagnosis |
Important nuance: MCI does not inevitably progress to dementia. Roughly 40% of MCI cases stabilise or even revert to normal — especially when vascular risk factors are treated. The key is early identification and aggressive lifestyle intervention: exercise, blood pressure control, sleep, and social engagement.
What it means for you
The MoCA test was specifically designed to detect MCI — it is more sensitive than the older MMSE for this purpose. A score of 18–25 suggests MCI territory and warrants clinical evaluation.
Medical disclaimer
This content is for educational purposes only and is not medical advice. Scores from online tests are not diagnostic - if you are concerned about symptoms such as memory loss, attention problems, or cognitive decline, consult a qualified clinician.
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Quick Answer
MCI is the clinical grey zone between normal aging and dementia - measurable cognitive decline beyond what's expected for age, but not severe enough to impair daily functioning. About 15–20% of people over 65 have MCI. Roughly 10–15% per year convert to dementia.
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