The Differences and Similarities Between Stroke and Dementia

Portrait of elderly man sitting at table
Jovana Milanko/Stocksy United

Stroke and dementia are two neurological conditions that have several overlapping features. It can be hard to tell the difference between a stroke and dementia. If you have questions about the similarities and distinctions between dementia and stroke, here are the answers to the most frequently asked questions about stroke vs. dementia. 

Differences between stroke and dementia


A stroke happens suddenly and the symptoms of a stroke can include weakness, slurred speech, language problems, changes in vision, numbness, loss of balance, trouble walking and confusion.

Any combination of these symptoms can happen with a stroke. 

Dementia is a gradual process. People with dementia experience problems with forgetfulness, confusion, inappropriate behavior, agitation, anger, paranoia and mood changes. Dementia does not cause weakness of the face, arm or leg. 


A stroke is a sudden event, while dementia is a slowly progressive illness that gets worse over time. But sometimes, family members do not notice early symptoms of dementia, so the problems may seem sudden. 

Causes of stroke and dementia

A stroke occurs when an interruption in blood flow to a region of the brain causes brain damage to the area of the brain that suffered from interrupted blood supply. A stroke may be caused by a blood clot blocking a blood vessel or by bleeding of the affected blood vessel (hemorrhage.) The specific consequences of a stroke correspond to the region of the brain that suffered ischemia or hemorrhage.

Dementia is caused by gradual deterioration of the regions of the brain that control memory, behavior or mood. 

Risk factors for stroke and dementia

The most common stroke risk factors include smoking, high blood pressure, heart disease, diabetes and high cholesterol. Most stroke risk factors are manageable, and if they are managed, stroke risk can be considerably reduced. 

Dementia may be genetic, but the actual cause is not well understood. However, we do know that a person who has had strokes may be at a higher risk of developing dementia. 

Are all strokes the same? Is all dementia the same?

All strokes are caused by a lack of blood supply, but there are different types of strokes with different symptoms and long-term effects based on which blood vessel in the brain was affected and which region of the brain was injured. For example, if a stroke affects the temporal region of the brain, it might cause a speech and language problem, while a stroke that affects the occipital areas of the brain can cause visual changes. 

There are a few different types of dementia, and some are characterized by forgetfulness, while others are associated with agitation or inappropriate behavior.

Can dementia cause a stroke?

Dementia cannot directly cause a stroke. However, people who have dementia are often unable to take medication as directed, and often experience strokes because of lack of self-care.


Can a stroke cause dementia?

A stroke can cause some of the symptoms of dementia. There is a type of dementia called vascular dementia, which results from having many small strokes or silent strokes in the regions of the brain that control memory and behavior. Any type of stroke can definitely make symptoms of dementia much more extreme.

At what age do people have dementia and stroke?

Strokes can occur at any age, but the majority of strokes happen after age 70. Dementia, similarly, tends to occur after the age of 75, but there are some types of dementia that begin as early as the 50’s and continue to worsen over the next years.

Is there medication for strokes and dementia?

There are emergency medications for stroke and there are stroke prevention medications, but there is not medication that can reverse the damage of a stroke. There are some medications for dementia, and they have been shown in research experiments to slow the progression of some types of dementia, but they do not reverse symptoms of dementia.


Cerebral small vessel disease: Capillary pathways to stroke and cognitive decline, Østergaard L, Engedal TS, Moreton F, Hansen MB, Wardlaw JM, Dalkara T, Markus HS, Muir KW, Journal of Cerebral Blood Flow and AMetabolism, October 2015

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