What Is Dementia?

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Dementia is a term that refers to a set of symptoms of cognitive decline that interfere with a person's daily functioning. Alzheimer's disease is a type of dementia, but there are several others. Dementia refers to cognitive symptoms that a person may display, such as memory loss, difficulty thinking clearly, trouble focusing, and an inability to control their emotions.

This article covers the definition of dementia, as well as its symptoms and causes. It also shares how dementia is typically diagnosed and ways that may help you cope physically and emotionally if you or a loved one has dementia.

Symptoms of Dementia

While the signs of cognitive decline may vary from person to person, the following are symptoms that are characteristic of dementia:

  • Confusion
  • Difficulty understanding others
  • Difficulty reading or writing
  • Hallucinations, delusions, or paranoia
  • Having a hard time speaking
  • Impulsivity
  • Loss of interest
  • Memory loss
  • Poor judgment
  • Problems with movement
  • Repeating themselves
  • Taking more time to complete tasks
  • Wandering and getting lost (even in familiar places)

The symptoms of dementia are often categorized into three stages: early-stage, middle-stage, and late-stage dementia. Symptoms increase and usually get progressively worse as someone moves from the early stage to the late stage.

Early Stage Dementia

It's common to overlook the symptoms of early-stage dementia. During this stage, a person may experience forgetfulness, losing track of time, and/or getting lost in familiar places. However, a person with early-stage dementia is generally still able to function independently.

Middle Stage Dementia

Symptoms often become more apparent when dementia progresses into this stage. A person may forget recent events or the names of people close to them. They may become easily confused, have trouble communicating, and repeatedly ask questions.

At this stage, a person may need help completing daily tasks, such as those involving personal hygiene. They may experience changes in personality as well, perhaps becoming agitated more easily. They may also have difficulty sleeping.

Late Stage Dementia

Symptoms become the most severe during late-stage dementia. People with late-stage dementia often require a full-time caretaker.

This stage may involve the following symptoms:

  • Bladder or bowel incontinence
  • Delusions (i.e., believing someone is "out to get them")
  • Hallucinations (seeing or hearing things that aren't there)
  • Increased memory loss
  • Paranoia (i.e., increased suspicion of those around them)
  • Reduced mobility (i.e., trouble walking, swallowing, eating, or dressing)

Diagnosis of Dementia

A doctor will likely conduct a physical exam, including bloodwork, to determine whether a person has another medical condition that may be contributing to the symptoms they're experiencing.

For instance, vitamin deficiencies, thyroid conditions, and excessive alcohol use may all cause symptoms such as difficulty focusing and remembering things and may be confused with dementia.

In addition, a doctor will ask about a person's medical history, whether or not dementia runs in their family, as well as what (if any) medications the person is currently taking.

If you or a loved one is experiencing symptoms of dementia, it's helpful to keep a timeline of when these symptoms began and whether they have become worse over time. A doctor will ask about the severity and duration of symptoms.

Unfortunately, there is no single test to diagnose dementia. As a result, doctors will need a lot of information to determine whether dementia is the cause of symptoms. They may conduct the following:

  • Brain scans: These may include computed tomography (CT) scans, magnetic resonance imaging (MRI), or positron emission tomography (PET). Brain scans can identify any changes in brain structure as well as strokes or tumors, which in some cases, may cause dementia.
  • Cognitive tests: A doctor may administer tests for memory, language, problem-solving skills, balance, and/or reflexes.
  • Psychiatric evaluation: In some cases, an underlying mental health condition (such as depression) may contribute to dementia-like symptoms such as difficulty remembering things or trouble concentrating. A psychiatric evaluation can help rule out another potential cause of your symptoms.

A doctor may conduct a blood test that measures a protein called beta-amyloid—people with Alzheimer's have a high level of beta-amyloid in the blood. There are also genetic tests available to measure someone's risk of developing dementia.

Genetic tests can determine whether someone carries a gene mutation for Alzheimer's or another gene that increases the risk of developing the disease.

However, genetic testing is most often done on people who aren't yet showing symptoms of dementia or on those who are in the early stage. A genetic counselor should be consulted prior to receiving this test; they can help you prepare yourself to receive the results, as it can be emotionally overwhelming.

It can take months for healthcare professionals to make an official diagnosis of dementia. For this reason, it's helpful if family members and loved ones continue to document signs and symptoms.

Causes of Dementia

Dementia is the result of damage to the brain cells. When the cells in the parts of the brain that control thinking and memory are damaged, for instance, these functions become impaired.

Researchers are still learning what actually contributes to the damage to these cells. Genetics are thought to play a role in the development of dementia; however, it's still possible to develop the condition even if it doesn't run in your family.

Some health conditions can also cause dementia, such as:

  • Creutzfeldt-Jakob disease: A rare and fatal neurodegenerative disorder
  • Huntington's disease: A breakdown of the brain's nerve cells
  • Parkinson's disease: People with late-stage Parkinson's may develop dementia
  • Wernicke-Korsakoff syndrome: A vitamin B1 deficiency that can result in bleeding in the brain

Risk Factors

There are some groups of people that are at a higher risk of developing dementia. Risk factors include:

  • Age: Most people with dementia are 65 years or older.
  • Family history: If a person's parent or sibling has dementia, their risk of developing the condition increase.
  • Health conditions: Some health conditions—such as high blood pressure and high cholesterol—increase a person's risk of developing dementia. Traumatic brain injuries (TBIs) may also increase the risk of developing dementia.
  • Race: On average, African American and Hispanic people have a higher risk of developing dementia than White people.

Types of Dementia

There are many different types of dementia. Some of the most common include:

  • Alzheimer's disease: Alzheimer's is the most common type of dementia. It's characterized by a slow, progressive degeneration of cells in the brain.
  • Frontotemporal dementia (FTD): This occurs when there is atrophy or deterioration of the frontal and temporal lobes of the brain, resulting in changes in behavior and a decline in motor skills.
  • Lewy body dementia (LBD): LBD occurs when the protein alpha-synuclein is deposited in the brain—these deposits are called Lewy bodies. As a result, changes in the brain lead to problems with memory, movement, and behavior.
  • Vascular dementia: Vascular dementia is characterized by reduced blood flow to the brain, which results in the impairment of cognitive abilities and executive functioning.
  • Mixed dementia: This describes when someone who has more than one type of dementia at a time.

Treatment for Dementia

Unfortunately, there is no cure for dementia. However, there are a number of treatment options, ranging from therapy to medication, that can potentially help improve symptoms and quality of life for those with the condition.


Someone with dementia will likely experience a range of emotions such as irritability, depression, anxiety, and apathy. Cognitive behavioral therapy (CBT) may help those with early- to middle-stage dementia learn adaptive coping mechanisms to process difficult feelings, reframe negative thoughts, and manage behavior.

In some cases, both a patient and a caregiver may attend therapy sessions together to address each of their issues and create a supportive environment for both people.

Reminiscence therapy may also help promote psychological well-being in people with dementia. During reminiscence therapy, a therapist encourages a client to recall memories of their own life.

A reminiscence therapist may use videos, recordings, photos, and more to help a person remember. This practice may benefit a person's mood and cognition, though more research is needed to understand its long-term effects.

Occupational and/or speech therapy may become helpful, especially as dementia progressively changes a person's ability to perform daily tasks or to use and understand language.

Music therapy and art therapy may improve the quality of life of someone with dementia. Engaging in enjoyable activities, in general, can help to boost mood and be a useful outlet.


The Food and Drug Administration (FDA) has approved a number of different medications to treat dementia. It's worth noting, however, that most of these medications were specifically designed for Alzheimer's disease.

Acetylcholinesterase Inhibitors

Acetylcholinesterase inhibitors approved to treat dementia include:

  • Aricept (donepezil)
  • Exelon (rivastigmine)
  • Razadyne (galantamine)

These medications are designed to slow cognitive decline in people with dementia. As with any medication, there are potential side effects linked with acetylcholinesterase inhibitors such as nausea, vomiting, and insomnia. Those with pre-existing health conditions such as respiratory disease or seizure disorders should use caution when taking these medications.

NMDA Receptor Antagonists

NMDA (N-methyl-D-aspartate) receptor antagonists such as Namenda (memantine) are sometimes prescribed for people with Alzheimer's disease. Memantine may improve the thinking abilities of someone with Alzheimer's; however, it is not a cure and won't prevent future cognitive decline. Side effects of NMDA receptor antagonists include headache, constipation, and dizziness.


An intravenous therapy called Aduhelm (aducanumab) is FDA-approved to treat mild cognitive impairment (MCI) or the mild dementia stage of Alzheimer's. It targets and removes amyloid plaques, which are thought to contribute to cognitive decline.

Some patients who've received Aduhelm had improved memory and language ability as well as improvements with doing tasks independently. However, a doctor must first determine a patient's eligibility with a cerebral spinal fluid analysis or positron emission tomography (PET).

Side effects of Aduhelm included microhemorrhages (blood in the brain tissue), superficial siderosis (excess iron in the brain and spinal cord), headache, fall, diarrhea, altered mental statuses, and amyloid related imaging abnormalities (ARIA). ARIA involves temporary swelling of the brain.

A caregiver should monitor a person's physical and mental health when they take medication for dementia. In some cases, a doctor may lower the dosage, or discontinue a medication altogether, if there are adverse effects.

Antidepressants and Antipsychotics

Of dementia patients, 63% experience depression. A doctor may recommend an antidepressant at a low dose, such as a selective serotonin reuptake inhibitor (SSRIs) like Lexapro (escitalopram). In some cases, a doctor may prescribe a medication to treat agitation or aggression in people with dementia.

However, the FDA issued a black box warning for people with dementia taking atypical antipsychotics like Risperdal (risperidone) and Seroquel (quetiapine). Especially in elderly adults with dementia, the risks of taking antipsychotics include stroke, heart failure, and even death.

A person with dementia taking an antipsychotic should be under close medical supervision, and should only take an antipsychotic for a short period of time such as a few weeks.

Coping With Dementia

Living with dementia is difficult, not only for the individual but also for their loved ones. However, there are resources that can help. You may find that speaking to a variety of specialists, such as a doctor, a social worker, and/or a therapist, can help you understand how to best manage dementia.


While someone with early-stage dementia is generally able to function independently, this changes as their condition progresses. If your loved one has dementia, you may want to consider hiring a caregiver who can help them with daily tasks.

It's also important that you and/or their caregiver monitor their condition to keep them safe. For instance, their ability to drive should be assessed regularly so that they are not in danger (or putting other drivers on the road at risk of harm).

A caregiver can make sure that no sharp objects are used without supervision, and that everyday tasks such as cooking are supervised.

It's often beneficial that people with mild to moderate dementia engage in social activities, which can benefit their well-being. Support groups may be helpful, especially those specifically for people with dementia or people who are experiencing cognitive decline.

Diet and Exercise

Someone with dementia may benefit from eating a diet that supports brain health; one example is a Mediterranean diet, which focuses on fruits and vegetables—specifically, leafy greens. Exercise is also important, such as walking, swimming, or weight-lifting. Diet and exercise can help support the physical and mental health of someone with dementia.

However, people with middle- to late-stage dementia should be monitored when engaging in physical activity. Anything strenuous or unsafe should be avoided.


If you are the caregiver of a loved one with dementia, it's important you keep in close contact with their doctor so that you have a full understanding of the health challenges your loved one will face. There are also support groups for family members and caregivers of those with dementia; you can find local groups through the Alzheimer's Association.

Be on the lookout for signs of caregiver burnout. You might be feeling tired, depressed, anxious, and stressed. Caregiving can take quite a toll on loved ones, so it's important to engage in self-care.

You might attend therapy sessions and make sure that you have time to yourself outside of caring for your loved one.

It's OK if you choose not to be your loved one's caregiver. In fact, choosing to hire a caregiver or having your loved one stay in an assisted living facility instead can enable you to better support them as their family member and friend, and reduce the stress you may feel from caring for them. Talk to a doctor or social worker about potential caregiving alternatives.

A Word From Verywell

Dementia can be intimidating to face, whether you have it or you are caring for a loved one who does. Remember, you're not alone. A caregiver can help you develop systems and lifestyle changes that can make your daily life easier. If you are a caregiver, there are resources that can help you cope as well to prevent burnout.

While there is no cure for dementia, there are treatment options that can greatly improve quality of life. Keeping in close contact with a doctor, therapist, and other healthcare professionals can feel reassuring as you receive as much information as possible about a dementia diagnosis.

21 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Institutes of Health. What is dementia? Symptoms, types, and diagnosis.

  2. Alzheimer's Society. The progression and stages of dementia.

  3. Duong S, Patel T, Chang F. Dementia: What pharmacists need to knowCan Pharm J (Ott). 2017;150(2):118-129. doi:10.1177/1715163517690745

  4. National Institutes of Health. Alzheimer's and hallucinations, delusions, and paranoia.

  5. Alzheimer's Association. What is dementia?

  6. Harvard Health Publishing. Is it dementia or depression?

  7. Alzheimer's Association. Genetic testing.

  8. Alzheimer's Association. Is Alzheimer's genetic?.

  9. Cleveland Clinic. Dementia.

  10. Centers for Disease Control and Prevention. What is dementia?

  11. Breijyeh Z, Karaman R. Comprehensive review on Alzheimer's disease: Causes and treatmentMolecules. 2020;25(24):5789. doi:10.3390/molecules25245789

  12. Leroy M, Bertoux M, Skrobala E, et al. Characteristics and progression of patients with frontotemporal dementia in a regional memory clinic networkAlz Res Therapy 2021;13(19). doi:10.1186/s13195-020-00753-9

  13. National Institutes of Health. What is Lewy body dementia? Causes, symptoms, and treatment.

  14. Venkat P, Chopp M, Chen J. Models and mechanisms of vascular dementiaExp Neurol. 2015;272:97-108. doi:10.1016/j.expneurol.2015.05.006

  15. Forstmeier S, Maercker A, Savaskan E, Roth T. Cognitive behavioural treatment for mild Alzheimer's patients and their caregivers (CBTAC): study protocol for a randomized controlled trialTrials. 2015;16:526. doi:10.1186/s13063-015-1043-0

  16. Woods B, O'Philbin L, Farrell EM, et al. Reminiscence therapy for dementiaCochrane Database Syst Rev. 2018;3(3):CD001120. doi:10.1002/14651858.CD001120.pub3

  17. Arvanitakis Z, Shah RC, Bennett DA. Diagnosis and management of dementia: ReviewJAMA. 2019;322(16):1589-1599. doi:10.1001/jama.2019.4782

  18. National Library of Medicine. Memantine.

  19. Alzheimer's Association. Aducanumab approved for treatment of Alzheimer's disease.

  20. Alzheimer's Association. Caregiver stress.

  21. Gérain P, Zech E. Informal caregiver burnout? Development of a theoretical framework to understand the impact of caregivingFront Psychol. 2019;10:1748. doi:10.3389/fpsyg.2019.01748

By Kristen Fuller, MD
Kristen Fuller is a physician, a successful clinical mental health writer, and author. She specializes in addiction, substance abuse, and eating disorders.