Disclaimer: This article has been researched using reputable medical sources but was not written by a healthcare professional. We hope it can help you start taking action toward better health, but meeting with a healthcare provider is recommended for guidance specific to your diagnosis and treatment.
If someone in your family has had dementia, you may have asked yourself the same two questions many people do: “Is this going to happen to me?” and “Is there anything I can do about it?”
The honest answer to both is: it depends. What causes dementia is not one single thing. Some dementia risk factors are out of your hands, like your age and your genes. But research shows that many others are things you can change, and together they may make a big difference.¹ ⁵ This guide explains the dementia risks you can’t control, the modifiable risk factors for dementia you can, and what the numbers really mean, including why dementia affects Black Americans at higher rates.
What Is Dementia, and How Is It Different From Alzheimer's?
Dementia is not one condition. It is a general term for a group of conditions that cause problems with memory, thinking, and daily life.¹ Alzheimer’s disease is the most common type, making up roughly 60 to 80 percent of cases.¹ ²
Dementia mostly affects older adults, but it is not a normal part of aging.¹ Forgetting a name now and then is common. Memory loss that gets in the way of everyday life is different, and it deserves a conversation with a doctor.
What Causes Dementia in the Brain?
In most cases, the exact cause is not known. Researchers have connected certain kinds of brain changes to certain types of dementia, but they are still learning why those changes start.² Here are the main types:
- Alzheimer’s disease
- Vascular dementia
- Lewy body dementia
- Frontotemporal dementia
- Mixed dementia
Scientists now know these conditions overlap more than they once thought. Vascular dementia, for example, is no longer seen as completely separate from the others.⁹
Dementia Risk Factors You Can't Control
Some risks cannot be changed, no matter how healthy your habits are. It helps to know them so you can be aware, not afraid.
Age. Age is the biggest risk factor. About 1 in 9 people age 65 and older has Alzheimer’s, and about three out of four people with Alzheimer’s are age 75 or older.⁴
Sex. Almost two-thirds of Americans living with Alzheimer’s are women.⁴
Genes and family history. Genes play a part in some cases. For a small number of people, rare gene changes directly cause dementia.² ³ Far more common is a gene called APOE, where one version (called ε4) is linked to a higher risk of late-onset Alzheimer’s.¹⁰ Having a risk gene does not mean you will get dementia, and many people with dementia do not have one.
Race and ethnicity. Older Black Americans are about twice as likely as older white Americans to have Alzheimer’s or another dementia.⁴ Race itself is not the cause. Researchers think a mix of health, social, and economic factors play a role, and we cover that below.⁸
Dementia Risk Factors You Can Control
The most important research on this topic comes from the Lancet Commission, an international group of experts. Their 2024 report named 14 risk factors that can be changed and estimated that around 45 percent of dementia cases worldwide might be preventable or delayed by addressing them.⁵ ⁶
These are the 14 factors:⁷
|
Risk Factor
|
What You Can Do
|
|---|---|
|
Get it checked, take prescribed medicine, and ask what your goal number is |
|
|
Get tested and talk with your doctor about food, activity, and medicine if needed |
|
|
Manage blood sugar with your care team |
|
|
Obesity |
Small, steady changes to food and movement, ideally with your doctor's support |
|
Physical inactivity |
Find movement you enjoy and can keep doing |
|
Smoking |
Quit with support (free help is available) |
|
Excessive alcohol use |
Cut back or avoid alcohol |
|
Hearing loss |
Get your hearing checked and treated |
|
Vision loss |
Get regular eye exams and treat vision problems |
|
Depression |
Talk with a doctor or counselor about treatment |
|
Social isolation |
Stay connected to friends, family, and community |
|
Traumatic brain injury |
Wear helmets and seat belts and take steps to prevent falls |
|
Air pollution |
Limit exposure when you can (for example, on high-pollution days) |
|
Less education |
Keep learning at any age |
Two of these, untreated vision loss and high LDL cholesterol, were added in the 2024 update.⁵
Can Dementia Be Prevented? What the "45%" Number Really Means
The 45 percent number is encouraging, but it is easy to misunderstand. Here is what it does and does not mean:
- It is an estimate for communities, not a promise for any one person. It describes how many cases might be prevented or delayed if these risks were fully addressed.⁵
- It does not mean dementia is anyone’s fault. Many people do everything “right” and still develop dementia, and many with several risk factors never do.
- Many “controllable” risks are shaped by life circumstances, such as where you live, what health care you can reach, how much education you had access to, and the air you breathe. Researchers note that falling dementia risk in some wealthier countries has mostly benefited people with higher income and more education.¹¹
So the best way to think about it is this: you can lower your risk and may delay dementia, but you cannot fully control it. And communities and systems have a role to play, too, not just individuals.
Why the Dementia Risk Is Higher in Black Americans
Older Black Americans are about twice as likely to have Alzheimer’s or another dementia as older white Americans.⁴ ⁸ The Alzheimer’s Association says researchers have not yet identified the exact cause.⁸
Here is what we know:
- Heart and blood vessel health may play a role. High blood pressure, diabetes, and stroke are more common in Black communities, and these are linked to vascular dementia and Alzheimer’s.⁸
- Social and economic factors matter. Some studies show that the difference shrinks a lot once overall health and socioeconomic factors are taken into account.⁸
- Barriers to care are real. Only about 20 percent of Black Americans say they face no barriers to excellent health care and support for Alzheimer’s or other dementias.⁸
That is why knowing your numbers (blood pressure, cholesterol, blood sugar), getting hearing and vision checked, and asking early questions about memory can matter so much.
7 Steps You Can Start This Week
You do not need to change everything at once. Pick one or two:
- Get your blood pressure checked, and ask what your target is.
- Ask about cholesterol and blood sugar tests at your next visit.
- Move your body most days, even a 10-minute walk.
- Schedule a hearing or vision check if it has been over a year.
- Reach out to someone by phone or in person this week.
- Cut back on alcohol and ask for help quitting smoking if either applies to you.
- Learn something new, even for 15 minutes a day.
For more ideas, see our guide: 7 Things You Can Do This Week to Protect Your Memory.
When to Talk to a Doctor About Memory Changes
Consider making an appointment if you or someone you love shows these early dementia signs:
- Forgets recent events or repeats the same questions often
- Has trouble with familiar tasks, like managing bills or following a recipe
- Gets lost in places that used to be familiar
- Has trouble finding words or following conversations
- Shows changes in mood, behavior, or personality
- Has memory problems that are getting worse or getting in the way of daily life
Some causes of memory problems, such as vitamin deficiencies, thyroid problems, or medicine side effects, can be treated. That is one more reason not to wait.
Frequently Asked Questions
Q: What causes dementia?
A: Dementia is caused by damage to brain cells and the connections between them. The damage can come from different things depending on the type, such as protein buildups in Alzheimer’s or Lewy body dementia, or reduced blood flow in vascular dementia. In most cases, the underlying cause is not fully known.
Q: Is dementia genetic?
A: Sometimes, but not usually in a direct way. Rare gene changes cause dementia in a small number of families. More often, genes like APOE raise risk without guaranteeing that someone will get dementia.
Q: What are the biggest risk factors for dementia?
A: Age is the biggest one, followed by genetics and family history. Changeable risks include high blood pressure, diabetes, hearing loss, depression, physical inactivity, smoking, and social isolation, among others.
Q: Can you prevent dementia?
A: Not completely, but you may be able to lower your risk or delay it. Experts estimate that around 45 percent of dementia cases worldwide could be prevented or delayed by addressing 14 modifiable risk factors.
Q: Why are Black Americans more likely to have dementia?
A: Older Black Americans are about twice as likely to have Alzheimer’s or another dementia. Researchers have not found one exact cause. Higher rates of heart disease, diabetes, and stroke, along with social and economic factors and barriers to care, likely play a role.
Q: Is dementia a normal part of aging?
A: No. Dementia mostly affects older adults, but it is not a normal part of getting older.
Q: Can memory loss be caused by something other than dementia?
A: Yes. Vitamin deficiencies, thyroid problems, depression, sleep problems, and some medicines can all affect memory, and some are treatable.
References
- CDC. (2024). About Dementia. Retrieved from Centers for Disease Control and Prevention: https://www.cdc.gov/alzheimers-dementia/about/index.html
- Alzheimers.gov. (2025). What Is Dementia?. Retrieved from National Institute on Aging: https://www.alzheimers.gov/alzheimers-dementias/what-is-dementia
- Mayo Clinic. (2024). Dementia: Symptoms and Causes. Retrieved from Mayo Clinic: https://www.mayoclinic.org/diseases-conditions/dementia/symptoms-causes/syc-20352013
- Alzheimer’s Association. (2026). Alzheimer’s Facts and Figures. Retrieved from Alzheimer’s Association: https://www.alz.org/alzheimers-dementia/facts-figures
- Livingston, G., et al. (2024, July 31). Dementia Prevention, Intervention, and Care: 2024 Report of the Lancet Standing Commission. Retrieved from The Lancet: https://www.thelancet.com/commissions-do/dementia-prevention-intervention-and-care
- Hara, Y. (2024, August 12). Targeting 14 Lifestyle Factors May Prevent Up to 45% of Dementia Cases. Retrieved from Alzheimer’s Drug Discovery Foundation: https://www.alzdiscovery.org/cognitive-vitality/blog/targeting-14-lifestyle-factors-may-prevent-up-to-45-of-dementia-cases
- How Prevalent Are Modifiable Dementia Risk Factors in Ireland? A 12-Year Observational Study in Community-Dwelling Older Adults. (Lists the 14 Lancet Commission risk factors). Retrieved from PubMed Central: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12606470/
- Alzheimer’s Association. (n.d.). Black Americans and Alzheimer’s. Retrieved from Alzheimer’s Association: https://www.alz.org/help-support/resources/black-americans-and-alzheimers
- National Institute on Aging. (2025). Advanced Understanding of Dementia Risk Factors, Genetics, and Disease Mechanisms. Retrieved from National Institute on Aging: https://www.nia.nih.gov/10-years-alzheimers-disease-and-related-dementias-research/advanced-understanding-dementia-risk
- National Institute on Aging. The Genetic Characterization of Dementia (study record NCT01867359). Retrieved from ClinicalTrials.gov: https://clinicaltrials.gov/study/NCT01867359
- Livingston, G. (2025). Prevention of Dementia: A Necessary Worldwide Agenda. Alzheimer’s & Dementia. Retrieved from PubMed Central: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12725832/
