Learning Center

Difference between Alzheimer's Disease and Dementia

“Dementia is a general term for memory and thinking problems, while Alzheimer’s disease is the most common type of dementia that causes those problems.”

What Is Alzheimer's Disease?

Alzheimer’s disease is a progressive brain disorder that slowly destroys memory, thinking skills, and the ability to carry out daily tasks. Over time, brain tissue shrinks, especially in areas involved in memory and reasoning. Symptoms worsen gradually, moving from mild forgetfulness to severe cognitive and functional decline. Eventually, individuals require full-time care. It is the most common cause of dementia, accounting for 60–80% of dementia cases.

How Alzheimer's Changes the Brain

Alzheimer’s disease gradually changes the brain in distinct, measurable ways. These changes affect memory, thinking, and behavior, and they begin years—even decades—before symptoms become noticeable. Alzheimer’s changes the brain by building up toxic proteins (plaques and tangles), shrinking brain tissue, destroying connections, triggering inflammation, and reducing key neurotransmitters. These changes progress silently at first, then gradually rob a person of memory, independence, and ultimately, physical function.

What Is Alcohol Dementia?

Alcohol dementia, often referred to as alcohol-related dementia (ARD), is a form of cognitive decline caused by long-term, heavy alcohol use. Excessive alcohol consumption can damage the brain directly through its toxic effects and indirectly through nutritional deficiencies (especially thiamine, or vitamin B1). In some cases, partial recovery is possible if the person stops drinking, eats a healthy diet, and receives proper vitamin supplementation (especially thiamine). However, advanced cases may result in permanent brain damage. In short, alcohol dementia is preventable and sometimes partially reversible, but it requires early recognition and complete abstinence from alcohol.

What is dementia with Lewy bodies?

Dementia with Lewy bodies (DLB) is a less common form of dementia that shares features with both Alzheimer’s disease and Parkinson’s disease. It is caused by the build-up of Lewy bodies—tiny clumps of protein that form inside nerve cells. These clumps disrupt chemical signals in the brain, preventing nerve cells from communicating properly. Over time, this damage leads to the death of brain cells and the symptoms associated with dementia.

Living with Lewy Body Dementia

It began with small changes — a forgotten word here, a misplaced item there. But over time, those moments grew harder to ignore. For the man you’re about to meet, the culprit was Lewy Body dementia — the second most common form of dementia after Alzheimer’s. The disease affects thinking, movement, and behavior. And unlike Alzheimer’s, symptoms can appear suddenly and fluctuate day to day. Right now, there is no cure. But researchers at Mayo Clinic are studying Lewy Body dementia closely, hoping their work will lead to better treatments — and a better quality of life — for patients and their families. Experts say early diagnosis is key, and ongoing research could offer new hope for those living with this devastating condition.

Examine Mayo Clinic's Studies & research

Knowledge and Information

What is a Gerontologist?

A gerontologist is a health care professional who studies and understands the aging process. Their work focuses on the physical, emotional, mental, and social changes that people experience as they grow older.

Gerontologists can be found in many places, including:

Hospitals – helping patients transition from hospital care to home or long-term care
Nursing homes & senior centers – supporting programs and services for older adults
Universities & research centers – studying ways to improve healthy aging
Community programs – connecting seniors and families with helpful resources

While gerontologists are not doctors, they play an important role on the care team. They work side by side with physicians, nurses, case managers, and other professionals to make sure older adults receive care that supports their health, independence, and quality of life.

LEARNING CENTER