Which of the following best describes dementia?

Dementia is best described as an abnormal condition characterized by cognitive deficits, which commonly include significant memory impairment. This decline in cognitive function can affect various areas such as reasoning, language, and the ability to perform everyday tasks. The definition encompasses various types of dementia, such as Alzheimer's disease, vascular dementia, and others, emphasizing the cognitive aspects of the condition rather than physical health or heredity.

The other options outline different aspects that don't accurately convey the essence of dementia. The first option incorrectly emphasizes a loss of physical health, which is not a defining characteristic of dementia per se. The third option limits dementia to a hereditary condition affecting only the elderly, which is an oversimplification, as while age is a risk factor, dementia can occur in younger populations as well. Lastly, the fourth option mischaracterizes dementia as merely a mental health disorder without recognizing the significant cognitive impairments that define it, along with potential physical manifestations related to the overall health of individuals with dementia.