What is Alzheimer's Disease?

Alzheimer's disease is the most prevalent type of dementia accounting for 60-80% of all dementia cases.1 Alzheimer’s disease causes brain cell death and ultimately leads to brain tissue shrinkage.2

Alzheimer's is the sixth leading cause of death in the United States and the fifth leading cause of death for adults aged 65 and older.In 2018 there were 5.5 million individuals with Alzheimer’s disease and that number is expected to rise to 13.8 million by 2050.Alzheimer’s Disease was also recently named the most feared disease of Americans, surpassing heart disease and cancer. In Tennessee, there are 120,000 individuals living with Alzheimer’s disease.4 Tennessee has the second-highest age-adjusted mortality rate due to Alzheimer’s disease in the United States.

Mild Cognitive Impairment (MCI) occurs when there are signs of cognitive decline. Although not everyone with Mild Cognitive Impairment goes on to develop Alzheimer’s disease, individuals with MCI are at great risk for developing Alzheimer’s disease.5 Up to 60% of people with MCI go on to develop dementia. For this reason, MCI is often considered to be a transitional state between healthy aging and dementia including Alzheimer’s disease.5

Alzheimer’s disease can be classified in stages to describe the disease progression and correlating symptoms.

The Early Stage

Alzheimer's can begin developing as soon as 20 years before symptoms such as memory loss begin.2  As the disease spreads it begins to affect different parts of the brain first affecting learning and memory and then thinking and planning.This explains why the main symptom associated with Alzheimer’s is memory loss as it is the first and primary part of the brain affected by the plaque and tangle build up.  

Mild Alzheimer’s 

People are often diagnosed in this stage. Memory begins to worsen, and behavioral changes occur. This is often when getting lost and wandering begin. The individual may also begin repeating questions and taking longer to complete normal daily tasks.3  

Moderate Alzheimer’s

Speaking and understanding worsens. Language, reasoning, sensory processing and conscious thought are all heavily affected in this stage.3 It becomes difficult to recognize individuals and objects. Additionally, hallucinations, delusions and paranoia may occur.3


Ultimately, severe Alzheimer’s leads to the inability to complete every day functions including bathing, dressing. By the final stage, plaques and tangles have spread throughout the brain, and brain tissue has shrunk significantly.3 People with severe Alzheimer’s cannot communicate and are completely dependent on others for their care. Near the end, the person may be in bed most or all of the time as the body shuts down.3

Currently there is no cure for Alzheimer’s or a way to slow the progression of the disease. However, there are care and symptom treatments available.

This Page Last Updated: October 11, 2021 at 1:35 PM