Final answer:
Dementia is the term for illnesses causing serious, progressive cognitive decline, with Alzheimer's disease being a prominent example. Alzheimer's is characterized by brain plaques leading to memory loss and impaired daily functions. Factors like genetics, environment, and diet impact the risk and progression of the disease.
Step-by-step explanation:
The term for any illness that produces serious, progressive, usually irreversible cognitive decline is dementia. This condition, often associated with old age, is characterized by symptoms such as disruptive memory loss, confusion about time or place, difficulty with planning and executing tasks, poor judgment, and personality changes. Diseases such as Alzheimer's disease fall under the umbrella of dementia, where we see a progression from preclinical stages to mild, moderate, and finally severe states. Alzheimer's disease in particular is notable for its characteristic plaques in the brain, which contribute to the death of neurons and result in severe cognitive and functional deficits that include forgetfulness and an inability to perform daily tasks.
Various factors influence the development of Alzheimer's, such as genetic basis, environmental factors (like exposure to lead, iron, and zinc), and nutritional aspects (for instance, adherence to the Mediterranean diet can lower the risk). While currently incurable, strategies such as cognitive rehabilitation and possibly virtual reality technologies are being explored to manage mild cognitive impairment and potentially slow the disease's progression.