Dementia is an umbrella term for a group of symptoms: a decline in memory, reasoning or other thinking skills that interferes with daily life. Alzheimer’s disease is a specific brain disease and the most common cause of dementia, behind roughly 60% to 80% of cases. So the two words are not interchangeable: everyone with Alzheimer’s has dementia once symptoms are significant, but not everyone with dementia has Alzheimer’s.
What is the difference between dementia and Alzheimer’s?
The Alzheimer’s Association describes dementia as a collection of cognitive, functional and behavioral symptoms caused by specific diseases. The CDC puts it simply: dementia is not a specific disease. Alzheimer’s is one of the diseases behind it.
| Dementia | Alzheimer’s disease | |
|---|---|---|
| What it is | A set of symptoms: loss of memory, reasoning or thinking skills that gets in the way of daily life | A specific, progressive brain disease |
| What causes it | Many diseases, including Alzheimer’s, vascular disease, Lewy body disease and frontotemporal degeneration | Abnormal clumps of protein (amyloid plaques and tau tangles) and loss of connections between nerve cells |
| How common | The whole group | About 60% to 80% of dementia cases |
| Typical first sign | Depends on the cause | Trouble remembering new information |
| Course | Usually worsens over time; some causes of dementia-like symptoms can be treated | Symptoms worsen gradually; there is no cure, though some medicines may help |
Sources: Alzheimer’s Association, CDC, the National Institute on Aging (NIA) and the New York State Department of Health.
Are Alzheimer’s and dementia the same thing?
No, though people use them that way because Alzheimer’s is so common. A useful way to remember it: dementia names what the person is experiencing, and Alzheimer’s is one possible reason. A doctor may tell a family “your mother has dementia” first, and only later, after testing, say which type.
Some people also have more than one cause at once. The NIA calls this mixed dementia, for example Alzheimer’s together with vascular dementia. Neither condition is a normal part of aging, though risk rises with age: the NIA says about one-third of people 85 or older may have some form of dementia, and many live into their 90s and beyond without any.
What are the common types of dementia?
The NIA’s overview of dementia types covers four main ones, plus mixed dementia:
| Type | What is happening in the brain | What the NIA lists among the symptoms |
|---|---|---|
| Alzheimer’s disease | Amyloid plaques and tau tangles build up | Repeating questions, wandering and getting lost; later, trouble recognizing family |
| Vascular dementia | Blood clots or damaged vessels disrupt blood flow to the brain | Forgetting events, misplacing items, trouble following instructions, poor judgment |
| Lewy body dementia | Deposits of the protein alpha-synuclein | Trouble concentrating or staying alert, visual hallucinations, muscle rigidity, sleep problems |
| Frontotemporal dementia | Abnormal tau and TDP-43 proteins in the frontal and temporal lobes | Changes in behavior and emotion, trouble planning, language problems; tends to start in people younger than 60 |
| Mixed dementia | Changes from two or more types at once | A combination, which can make diagnosis harder |
Other conditions can also cause dementia, including normal pressure hydrocephalus, Huntington’s disease and long-term heavy alcohol use. Dementia that follows Parkinson’s disease is covered in our Parkinson’s care guide, and stroke-related changes in our stroke recovery guide.
How are early signs different from normal aging?
Everyone forgets a name now and then. The NIA’s comparison of age-related forgetfulness and signs of dementia turns on how often it happens and what it disrupts:
- Age-related forgetfulness: a bad decision once in a while, a missed monthly payment, forgetting the day and remembering later, occasionally searching for a word, losing things from time to time.
- Signs of dementia: poor judgment much of the time, problems managing monthly bills, losing track of the date or time of year, trouble having a conversation, often misplacing things and being unable to find them.
The first signs also depend on the cause. Alzheimer’s usually starts with trouble remembering new information, while some other types begin with changes in behavior, language, movement or alertness. Our guide to early detection and risk has the Alzheimer’s Association’s full list of ten warning signs. If confusion appears suddenly rather than gradually, it may be delirium and needs prompt medical attention; see delirium vs dementia.
How is dementia diagnosed, and how is Alzheimer’s diagnosed?
Both start the same way. There is no single test, and the NIA says doctors first look for treatable conditions behind the symptoms, since thyroid, kidney or liver problems, vitamin deficiencies and medication side effects can cause memory problems that resemble dementia.
- History and exam. The doctor asks the person, and ideally a family member or friend, about health, medicines, daily activities and changes in behavior, and checks blood pressure and other vital signs.
- Blood and other lab tests. These look for other causes, such as vitamin or hormone problems.
- Thinking and memory tests. Tests of memory, problem solving, attention, counting and language, sometimes with balance and reflex checks.
- Brain scans. CT or MRI can find strokes, tumors or other problems; PET scans can show brain activity or specific molecules.
- Specialist review, if needed. The NIA names geriatricians, neurologists, geriatric psychiatrists, neuropsychologists and memory clinics.
- Extra tests for Alzheimer’s. Spinal fluid tests and, where available, a beta-amyloid blood test can add information. The NIA says blood test results alone should not be used to diagnose dementia.
Doctors may repeat tests over time, and the NIA advises people with memory problems to return every six to 12 months. Some tests may not be covered by insurance, so ask first. The NIA also lists the benefits of an early diagnosis: time to plan for the future, handle financial and legal matters, address safety issues and build support.
What can a New York family do first?
You do not need a diagnosis to start. Here is a sensible order, based on what the sources above recommend:
- Book a visit with the person’s doctor. Write down what you have noticed, when it started, and what medicines the person takes. Go along if they agree.
- Ask about a cognitive assessment. Medicare Part B covers a separate visit to review thinking and memory, confirm or establish a diagnosis and make a care plan. After the Part B deductible you pay 20% of the Medicare-approved amount, and you can bring a spouse, friend or caregiver.
- Find a specialist. The New York State Department of Health lists ten Centers of Excellence for Alzheimer’s Disease that diagnose and manage dementia, searchable by county.
- Call a helpline for guidance. See the table below.
- Start the paperwork conversation early. Our guide to power of attorney and guardianship covers the options. The NIA lists financial and legal planning among the benefits of an early diagnosis. Consult an elder law attorney for your situation.
| Where to call | What it offers | Phone |
|---|---|---|
| Alzheimer’s Association Helpline | 24/7 information and referral for people with memory loss and caregivers | 1-800-272-3900 |
| CaringKind Helpline (New York City) | Navigators and specialists trained in dementia answer questions about programs and services | (646) 744-2900 |
| NYC Aging, Aging Connect | Caregiver programs: information, benefits counseling, training, support groups, respite | 212-244-6469 |
| NY Connects (listed by the NYS Office for the Aging) | Statewide contact for information and referrals to programs for older adults | 1-800-342-9871 |
| NIA ADEAR Center | Publications and referrals to local and national resources on Alzheimer’s and related dementias | 800-438-4380 |
The state’s Alzheimer’s Disease Community Assistance Program, delivered through seven New York Alzheimer’s Association chapters, also provides care planning, caregiver education and support groups, and the Regional Caregiver Support Initiative includes respite. Find both on the Department of Health page linked above. The Department estimates that about 426,500 New York residents have Alzheimer’s or a related dementia, so you are far from alone.
How does home care help with dementia or Alzheimer’s?
Home care does not treat the disease; the doctor does. It covers the daily needs around it. Whatever the type, people with dementia eventually need help with routines, safety and personal care, and the need lasts a long time. The New York State Department of Health says people with Alzheimer’s live an average of eight years after symptoms become noticeable, with a range of four to 20.
In practice, a home health aide or personal care aide can help with bathing, dressing, meals, reminders and keeping a familiar daily routine, while family keeps being family. Our dementia care guide explains how needs shift by stage, and our Alzheimer’s care page describes the service. For evening confusion, see sundowning care. When the person needs round-the-clock supervision, live-in care and respite care are the options to compare.
Paying for it is a separate question. Medicare does not cover most daily supervision, and New York Medicaid may; read what Medicaid covers for home care and what Medicare covers. When home stops being workable, when it is time for memory care lays out the signs.
Dementia care at home: advice from our nurse director
Anna Klyauzova, RN, MSN, MPA, Director of Patient Services at ProLife Home Care, on what she sees in practice:
You can’t do all of it by yourself. Alzheimer’s and other dementias change the whole family’s life, not only the patient’s. The sooner support is in place, the easier it is to keep a familiar routine and a safe home. Even a few hours of professional home care a week gives relatives time to rest.
Families rarely hear this: don’t argue with the person and don’t keep correcting mistakes. If your mother asks the same question for the fifth time, she isn’t doing it on purpose. A calm voice, a familiar room and a routine she can predict usually work better than long explanations.
We are a licensed home care agency in Brooklyn and Queens, licence #2572L001, New York State Department of Health. If you are working out what kind of help fits, call (718) 232-2777 or use our contact page.
Medical and benefit information changes. Everything above was checked on 12 October 2026 against alz.org, nia.nih.gov, cdc.gov, health.ny.gov, medicare.gov, nyc.gov and caringkindnyc.org. This page is general information, not medical or legal advice. Ask the person’s doctor about diagnosis and treatment, and never start, stop or change a medicine without the prescriber.
Frequently asked questions
What is the main difference between dementia and Alzheimer’s?
Dementia is a group of symptoms that affect memory, reasoning and daily life. Alzheimer’s is a specific disease that causes those symptoms and accounts for about 60% to 80% of cases. Other causes include vascular, Lewy body and frontotemporal disease.
Can you have dementia without having Alzheimer’s?
Yes. Vascular dementia, Lewy body dementia and frontotemporal dementia are separate causes, and some people have mixed dementia with more than one. A doctor can tell you which applies after an evaluation.
Is Alzheimer’s worse than dementia?
The question mixes two levels. Alzheimer’s is one cause of dementia, not a worse version of it. How fast symptoms progress varies by person and by type, so ask the person’s doctor what to expect.
What are the first signs of dementia?
They depend on the cause. In Alzheimer’s, trouble remembering new information is typical. Other types may start with changes in behavior, language, movement, attention or alertness. A pattern that disrupts daily life is a reason to see a doctor.
Who diagnoses dementia in New York?
Usually the primary care doctor first, then a neurologist, geriatrician, geriatric psychiatrist or neuropsychologist if needed. The state Department of Health lists ten Centers of Excellence for Alzheimer’s Disease by county.
Does Medicare pay for a memory evaluation?
Medicare Part B covers a separate visit for a cognitive assessment and care plan. After the Part B deductible you pay 20% of the Medicare-approved amount. Ask the provider what it will cost.
Who can I call in New York for help with a parent’s memory problems?
The Alzheimer’s Association Helpline (1-800-272-3900, 24/7), the CaringKind Helpline in New York City ((646) 744-2900), NYC Aging’s Aging Connect (212-244-6469) and NY Connects (1-800-342-9871) are good starting points.
