Per the 2017 Alzheimer's Disease Facts and Figures [PDF] report published by the Alzheimer’s Association, there is now a distinction made between Alzheimer’s disease and Alzheimer’s dementia.

This change in language comes at a time when researchers, scientists, and physicians seek to diagnose and treat this irreversible neurodegenerative condition long before cognitive impairment manifests.
 

What Is Alzheimer’s Disease?


The term Alzheimer’s disease refers to the entire process of neurodegeneration. The disease process spans many years where a person is living with biological markers that are indicative of risk factors of the disease and may have no symptoms, to the stage where functional cognitive impairment is evident, to the end stage of the disease process.
 

What Is Alzheimer’s Dementia?


When a person has reached the stage of impaired functional cognition, evident by impaired thinking, memory, and behaviors, one is said to have Alzheimer’s dementia.
 

Alzheimer’s Dementia Statistics


Prevalence statistics from the report include:
  • An estimated 5.5 million Americans age 65 and older have Alzheimer’s dementia in 2017.
  • 5.3 million are 65 years old and older.
  • One in 10 people age 65 and older has Alzheimer’s dementia.
  • 200,000 are below the age of 65 with early onset.
  • 82% of the people with Alzheimer’s dementia are 75 years old and older.
  • Fewer than half of the people living with this condition are aware of their diagnosis.
Read more about Alzheimer’s and dementia: