What Is Dementia?


What Is Dementia?

Dementia is a broad term that refers to the deterioration of cognitive functioning. This includes problems with thinking, remembering, learning, judgment, reasoning, and language. Although a decline in many of these areas is part of the aging process, a person with dementia will have deterioration beyond what is normal at their age.

That said, the longer you live, the more likely it will be that you have some form of dementia. In fact, up to half of all people over the age of 85 may have some form of dementia.

Dementia covers a wide range of specific medical conditions including Alzheimer’s — which is the most common form of dementia — Lewy body dementia, vascular dementia, frontotemporal dementia, and mixed dementia, which is a combination of two or more types of dementia.


The symptoms of dementia vary depending on the specific type and progression of that disease. Early on, symptoms are often minor, with a gradual onset. Because of this, dementia may go unnoticed by friends or family. As cognitive decline progresses, symptoms become more noticeable, and routine tasks such as caring for yourself become more difficult to perform, eventually leading to an interruption in daily living and independent functioning. 

Some of the more common symptoms of dementia include:

  • Forgetfulness
  • Memory loss
  • Mood changes
  • Difficulty concentrating
  • Problems with reasoning and judgment 
  • Confused about time and place
  • Getting lost in familiar settings
  • Forgetting the names of family and close friends
  • Difficulty carrying out familiar daily tasks
  • Problems with language, difficulty finding the right words
  • Withdrawal from socializing
  • Changes in executive functioning (difficulty carrying out multiple steps or with planning)


There is no one cause of dementia. That said, all types of dementia stem from damage to the brain cells. Moreover, each type of dementia may be associated with different damage and different regions of the brain. In general, the damage to the brain cells interferes with their ability to communicate with each other, which leads to problems with behavior and thinking.

Symptoms of dementia can also be caused by conditions like depression, vitamin B12 deficiency, thyroid disorders, Wernicke-Korsakoff syndrome, normal pressure hydrocephalus, or by taking certain medications. But unlike Alzheimer’s and other progressive brain diseases, these causes of dementia symptoms may be reversible. 

The Centers for Disease Control and Prevention says the strongest risk factor for dementia is increasing age. Many of the symptoms are common in people as they get older, however, they say most cases of dementia affect people 65 years and older. Additionally, they cite family history, poor heart health, traumatic brain injury, and race/ethnicity as factors that increase the risk of dementia.


There are several types of dementia. The following are the most common.

Alzheimer’s Disease

This accounts for 60% to 80% of cases, is a progressive brain disease that impacts memory, thought process, behavior, and the ability to remember newly learned information.

Vascular Dementia

Vascular dementia happens as a result of inadequate blood flow to various regions of the brain. This type of dementia changes thinking skills, especially following a stroke. Estimates put vascular dementia after Alzheimer’s as the second most common form of dementia, accounting for 5% to 10% percent of cases. 

Lewy Body Dementia

Lewy body dementia results from abnormal microscopic deposits that damage brain cells over time. This is the third most common type of dementia after Alzheimer’s and vascular dementia. Symptoms include changes in thinking and reasoning, confusion, slowness, sleep disturbances, and more. 

Frontotemporal Dementia

This refers to a group of disorders, is caused by progressive nerve cell loss in the brain’s frontal or temporal lobes. Symptoms include a deterioration in behavior and personality and difficulty with language, both producing and comprehending. 

Mixed Dementia

This is a combination of two or more types of dementia, is common in the elderly.  Someone with Alzheimer’s and vascular dementia is an example of mixed dementia. 


Since dementia is an umbrella term that describes the decline in cognitive functioning, resulting in different types of dementia, there is no one test to determine if someone has the condition. With that in mind, your doctor will conduct a thorough physical exam that also includes an in-depth medical history, laboratory test, and brain scans like a CT or MRI to determine if the symptoms you are exhibiting are related to dementia.

Depending on the doctor’s training, they may be able to conduct further evaluations to determine the type of dementia. Otherwise, they may need to refer you to a specialist such as a neurologist who can make an accurate diagnosis. 


Treatment of dementia depends on the type and underlying cause. Unfortunately, for several forms of dementia, like Alzheimer’s, there is no known treatment to stop the progression of the disease. However, there are interventions your doctor can recommend, such as medications that may temporarily decrease the severity of the symptoms, psychotherapy, and lifestyle changes.


There are several FDA-approved drugs available to treat the symptoms of dementia, especially in Alzheimer’s disease. For mild to moderate Alzheimer’s, your doctor may recommend drugs like Razadyne® (galantamine), Exelon® (rivastigmine), and Aricept® (donepezil) to help reduce symptoms and control behavior.

As the disease progresses, your doctor may recommend a medication called Namenda® (memantine) that is appropriate for moderate to severe cases of Alzheimer’s. This drug may help decrease symptoms and allow you to maintain daily functions longer than you would without medication. 


Your doctor may also recommend palliative care, psychotherapy, or counseling to help you understand the diagnosis and learn new ways to cope. The goal of this type of treatment is to improve your quality of life. For family members and caregivers, family counseling should be considered. 

Memory Care Facility

When dementia progresses to its most severe stage, families may need to consider permanent placement in a memory care facility. This typically happens when it becomes difficult to care for someone at home. Memory care can take place in a specialized unit at an assisted living facility or in a skilled residence that only houses people with severe forms of dementia like Alzheimer’s disease. 


If you or someone you love is dealing with the symptoms of dementia, it’s critical to practice self-care and reach out for help. Although certain types of dementia, like neurodegenerative dementias, have no cure, your doctor may try drug treatments and other lifestyle modifications to temporarily ease symptoms and help with daily living.

They may also recommend counseling for both the patient and the caregiver. When diseases like Alzheimer’s begin to progress, it may be necessary for the support person to reach out for additional help such as in-home care, assisted living, or permanent care in a memory care facility. 

9 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. World Health Organization. Dementia. September 2019. 

  2. National Institute on Aging. What is dementia? Symptoms, Types, and Diagnosis. December 2017.

  3. MedlinePlus. Dementia. May 2020. 

  4. Alzheimer’s association. What is dementia? 2020.

  5. Centers for Disease Control and Prevention. What is dementia? April 2019. 

  6. Alzheimer’s association. What is Alzheimer’s disease? 2020.

  7. Alzheimer’s association. Types of dementia. 2020.

  8. National Institute on Aging. What is mixed dementia? Causes and diagnosis. December 2017.

  9. Alzheimer’s association. Medications for memory loss. 2020. 

By Sara Lindberg, M.Ed
Sara Lindberg, M.Ed., is a freelance writer focusing on mental health, fitness, nutrition, and parenting.