Educational resource
Understanding Dementia
Dementia is not a single disease — it is an umbrella term for a group of symptoms affecting memory, thinking, and the ability to perform everyday activities. Learning what dementia is, and what it is not, is the first step toward supporting someone you love.
What is dementia?
Dementia describes a decline in cognitive function severe enough to interfere with daily life. It is caused by damage to brain cells that affects their ability to communicate with each other. Different types of dementia are associated with different types of cell damage in different regions of the brain.
Dementia is not a normal part of aging. While the risk increases with age, many people live into their 90s without developing dementia. It is also not the same as occasional forgetfulness — the changes associated with dementia are persistent, progressive, and affect multiple areas of thinking.
Common types of dementia
Alzheimer's disease
The most common cause of dementia. Characterized by plaques and tangles in the brain that disrupt cell communication and eventually cause cell death. Memory loss — especially of recent events — is often the first noticeable symptom.
Vascular dementia
Caused by reduced blood flow to the brain, often following a stroke or series of small strokes. Symptoms may appear suddenly and can include problems with reasoning, planning, and judgment.
Lewy body dementia
Caused by abnormal protein deposits (Lewy bodies) in the brain. Symptoms include visual hallucinations, fluctuating alertness, and movement problems similar to Parkinson's disease.
Frontotemporal dementia
Affects the frontal and temporal lobes of the brain. Often presents with changes in personality, behavior, and language rather than memory loss, and tends to occur at a younger age.
Mixed dementia
A combination of two or more types of dementia occurring simultaneously. Alzheimer's combined with vascular dementia is the most common form.
"Dementia is not a normal part of aging — and understanding the difference between normal forgetfulness and dementia is one of the most important things a family can learn."
10 early warning signs
The Alzheimer's Association identifies ten warning signs that may indicate dementia. If you notice several of these in yourself or someone you love, speak with a doctor.
Memory loss that disrupts daily life
Forgetting recently learned information, important dates, or events; asking the same questions repeatedly.
Challenges in planning or solving problems
Difficulty following a familiar recipe, keeping track of monthly bills, or concentrating on tasks that require numbers.
Difficulty completing familiar tasks
Trouble driving to a familiar location, managing a budget, or remembering the rules of a favorite game.
Confusion with time or place
Losing track of dates, seasons, and the passage of time; forgetting where they are or how they got there.
Trouble understanding visual images
Difficulty reading, judging distance, or determining color or contrast — which can cause problems with driving.
New problems with words
Stopping in the middle of a conversation, struggling to find the right word, or calling things by the wrong name.
Misplacing things and losing the ability to retrace steps
Putting things in unusual places and being unable to go back over their steps to find them.
Decreased or poor judgment
Changes in decision-making, such as giving large amounts of money to telemarketers or paying less attention to personal hygiene.
Withdrawal from work or social activities
Removing themselves from hobbies, social activities, or other engagements they previously enjoyed.
Changes in mood and personality
Becoming confused, suspicious, depressed, fearful, or anxious — especially when outside their comfort zone.
The stages of dementia
Dementia typically progresses through three broad stages, though the pace and specific symptoms vary widely from person to person.
Early stage
The person is largely independent. They may notice memory lapses, have difficulty finding words, or get lost in familiar places. Many people in early-stage dementia can continue to drive, work, and participate in social activities.
Middle stage
This is typically the longest stage. The person needs more help with daily activities. They may become confused about where they are, have trouble recognizing family members, and experience significant personality changes.
Late stage
The person requires full-time care. They may lose the ability to communicate verbally, become unaware of their surroundings, and need assistance with all activities of daily living including eating and personal hygiene.
This page provides general educational information only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about a medical condition.