Dementia is a neurodegenerative disease that has several forms, symptoms, and causes. There’s no cure, but researchers are looking into effective treatments and ways to prevent it.

It’s natural for your cognitive function — your ability to think, remember, and reason — to decline somewhat as you age. But in some people, the loss of cognitive function can be so extensive that it can affect their daily lives, emotions, and even personalities. This is known as dementia.

While cognitive decline is a natural part of aging, dementia is not. But dementia becomes much more common with advanced age.

Keep reading to learn more about dementia, how to recognize it, how it progresses, and how to manage it.

Dementia is a severe decline in cognitive function. This condition may affect one or more of the following functions:

  • memory
  • thinking
  • language
  • judgment
  • behavior

A variety of health conditions or injuries may contribute to dementia. Its effects can range from mild to severe. It may also cause personality changes.

Some types of dementia are progressive, which means the symptoms change over time and can become worse. Some types are treatable or even reversibleTrusted Source, and some experts may use the term “dementia” only to describe an irreversible decline in mental capabilities.

Dementia vs. major neurocognitive disorder

The official medical term for dementia is “major neurocognitive disorderTrusted Source.” The Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) made this change to describe the condition more accurately and to avoid the stigma associated with the term “dementia,” which comes from the LatinTrusted Source for “being out of one’s mind.”

How common is dementia?

According to the World Health Organization (WHO), about 55 million peopleTrusted Source in the world have dementia, and around 10 million new cases are reported each year.

The number of people receiving dementia diagnoses or living with dementia is increasing, partially as a result of increasing life expectancy.

The Alzheimer’s Association estimates that 6.9 million U.S. adults ages 65 years and older were living with Alzheimer’s disease (the most common type of dementia) in 2024, but that number could double by 2060.

In its early stages, dementia can cause symptoms such as:

  • Difficulty coping with change: Someone may have trouble accepting changes in their schedule or environment.
  • Subtle changes in short-term memory: Someone can remember an event that happened 15 years ago as if it were yesterday, but they can’t remember what they had for lunch.
  • Difficulty finding the right words: Someone may have more trouble recalling the words they want to use.
  • Repetitive speech or actions: Someone may ask the same question, complete the same task, or tell the same story multiple times.
  • Confused sense of direction: Places someone once knew well may now feel unfamiliar. Someone may also have trouble driving routes they’ve taken for years because the places no longer look familiar.
  • Struggling to follow storylines: Someone may find it challenging to follow a story or a description.
  • Changes in mood: Depression, frustration, and anger are common in people with dementia.
  • Loss of interest: People with dementia may experience apathy, such as a loss of interest in hobbies or activities they once enjoyed.
  • Confusion: People, places, and events may no longer feel familiar. Someone might not remember people who know them.
  • Difficulty completing everyday tasks: A person in the early stages of dementia may have trouble recalling how to do tasks they’ve done for many years.

Dementia has many causes. In general, it results from the breakdown of neurons (brain cells) or from disturbances in other body systems that affect how neurons work.

Several common causes of dementia are neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease. These diseases affect synapses (neuron-to-neuron connections that allow your brain to pass on messages).

Frontotemporal lobar degeneration is damage to the frontal and temporal lobes of the brain. Examples of conditions that cause this include:

Other medical conditions that may contribute to dementia include:

Doctors classify the type of dementia based on the specific condition that causes it. According to Dementia UK, there are more than 200 subtypes. The most common types of dementia are as follows:

  • Alzheimer’s disease: Alzheimer’s disease is the most common type, making up 60% to 80% of dementia cases, according to the Alzheimer’s Association.
  • Vascular dementia: Reduced blood flow to the brain causes vascular dementia. It may result from plaque buildup in arteries that feed blood to the brain or from a stroke.
  • Lewy body dementia: In Lewy body dementia, protein deposits in nerve cells prevent the brain from sending chemical signals, resulting in lost messages, delayed reactions, and memory loss.
  • Parkinson’s disease dementia: People with advanced Parkinson’s disease may develop dementia. Symptoms of Parkinson’s disease dementia include problems with reasoning and judgment, as well as increased irritability, paranoia, and depression.
  • Frontotemporal dementia: Several types of dementia fall into this category, each involving changes in the front and side areas of the brain. Symptoms include difficulty with language and behavior and loss of inhibitions. This is the most common type of dementia in people with amyotrophic lateral sclerosis (ALS).

Other types of dementia are rare. For example, Creutzfeldt-Jakob disease occurs in only 1 in 1 million people per yearTrusted Source.

Because dementia has many possible causes, a person can have multiple types of dementia at the same time. Doctors call this mixed dementia. The most common combination is Alzheimer’s and vascular dementia.

What is LATE?

Limbic-predominant age-related TDP-43 encephalopathy (LATE)Trusted Source is a newly discovered type of dementia that researchers are still studying. It results from the buildup of misfolded TDP-43 proteins in the brain.

The symptoms of LATE are similar to those of Alzheimer’s, but there’s no way to diagnose it in living people. Doctors don’t know whether someone had LATE until they can biopsy the brain after death.

Autopsy studies suggest that more than one-third of people over 85 years old may have LATE.

In most cases, dementia is progressive, which means the symptoms change over time and may get worse. The condition progresses differently in each person, but most people experience symptoms of the following stages of dementia.

Mild cognitive impairment

Some older adults may develop mild cognitive impairment (MCI) that does not progress to dementia or any other mental impairment. People with MCI commonly experience forgetfulness, difficulty recalling words, and short-term memory problems.

Mild dementia

People with mild dementia may be able to live independently. The symptoms can include:

  • short-term memory lapses
  • personality changes, including anger or depression
  • a tendency to misplace things
  • forgetfulness
  • difficulty with complex tasks or problem solving
  • difficulty expressing emotions or ideas

Moderate dementia

Someone who is experiencing this stage of dementia may need help from a loved one or caregiver because dementia may now interfere with daily tasks and activities. The symptoms include:

  • difficulty making decisions
  • increasing confusion and frustration
  • memory loss that reaches further into the past
  • difficulty with tasks such as dressing and bathing
  • significant personality changes
  • sundowning (worsening of certain symptoms later in the day)

Severe dementia

At this late stage of dementia, the mental and physical symptoms of the condition continue to worsen. Symptoms can include:

  • decline and eventual loss of certain bodily functions, including walking, swallowing, and bladder control
  • increasing difficulty with communication
  • a need for full-time help
  • an increased risk of infections

People with dementia will progress through the stages of dementia at different rates.

No single test can confirm a dementia diagnosis. Instead, doctors will use a series of tests and exams, such as:

  • a thorough medical history and family history
  • a careful physical exam
  • a review of symptoms, including changes in memory, behavior, and brain function
  • blood and urine tests to check for infections or rule out other conditions
  • a cerebrospinal fluid test (aka lumbar puncture or spinal tap) to check for proteins that may indicate neurodegenerative disease
  • cognitive tests to evaluate thinking, memory, and problem-solving skills
  • brain scans to observe the brain and rule out other causes of cognitive problems

Doctors can determine with a high degree of certainty whether you or a loved one is experiencing symptoms of dementia. However, they may not be able to determine the exact type of dementia. In many cases, symptoms of dementia types overlap, making it difficult to distinguish between types.

Some doctors will diagnose dementia without specifying the type. In that case, you may want to consult a doctor who specializes in diagnosing and treating dementia — typically, this doctor will be a neurologist. Some geriatricians also specialize in this type of diagnosis.

There’s typically no cure for dementia, but treatments are available to help manage the symptoms. Doctors may recommend medications or nondrug therapies.

Medications for dementia

The Food and Drug Administration (FDA) has approved some dementia medications to improve cognitive function:

  • Cholinesterase inhibitors: These medications increase levels of a chemical called acetylcholine, which may help with memory formation and improve judgment. Examples include:
  • Memantine (Namenda): This drug may delay the onset of cognitive and behavioral symptoms in people with moderate or severe Alzheimer’s disease. Memantine may allow people with Alzheimer’s to maintain their usual mental functions for longer.
  • Monoclonal antibodies: These are laboratory-made proteins that in the brain that contribute to Alzheimer’s. FDA-approved options include donanemab (Kisunla) and lecanemab (Leqembi). You receive them intravenously. A previous option, aducanumab (Aduhelm), was discontinued in November 2024.

Nondrug therapies for dementia

Nondrug therapies may help reduce symptoms of dementia and relieve some of the manageable complications of the condition. Common nondrug treatments for dementia include:

  • Changes to your environment: Clutter, noise, and overstimulation may reduce focus.
  • Changes to common tasks: A therapist or another healthcare professional can help you break down everyday activities, such as showering and grooming, into manageable tasks.
  • Occupational therapy: Occupational therapists are specialized healthcare professionals who can help you learn to be safer and more secure while performing tasks such as walking, cooking, and driving.

For decades, doctors and researchers believed dementia was not preventable. However, new research suggests that may not be the case.

A 2024 report suggests that up to 45%Trusted Source of dementia cases may be preventable. The report identified 14 modifiable risk factors:

The researchers believe that targeting these risk factors with treatment or intervention could delay or possibly prevent some cases of dementia.

Dementia risk and alcohol

Alcohol use may be the most preventable risk factor for dementia. A 2018 studyTrusted Source found that most cases of early onset dementia were related to alcohol use.

The researchers found that alcohol use disorders could increase a person’s risk of dementia threefold.

Experts recommend that people limit alcohol consumption to moderate levels — no more than one drink per day for females and two drinks per day for males — for overall health.

People can and do live for years after receiving a dementia diagnosis. Because of this, it may seem like dementia is not a fatal disease. However, late stage dementia eventually leads to death.

It’s difficult for doctors to predict life expectancies in people with dementia, and the factors that influence life expectancy may affect each person differently.

A 2019 study in Sweden found that the median survival time after diagnosis was 5.1 years for females and 4.3 years for males.

A 2020 study in the Netherlands found that the median time from diagnosis was 3.9 years to move to a care facility and 5 years until death.

Certain risk factors increase the likelihood of death in people with dementia, including:

  • increased age
  • decreased capabilities and functionality
  • additional medical conditions, diseases, or diagnoses, such as diabetes or cancer

However, it’s important to remember that dementia doesn’t follow a specific timeline. You or your loved one may progress through the stages of dementia slowly, or the progression may be rapid and unpredictable. This will affect life expectancy.

Dementia and Alzheimer’s disease are not the same. “Dementia” is an umbrella term for a collection of symptoms related to memory, language, and decision making.

Alzheimer’s disease is the most common type of dementia. The symptoms of Alzheimer’s may be similar to those of other dementia types but may also include depression, impaired judgment, and difficulty speaking.

Scientists worldwide are working to better understand many aspects of dementia. This research might help them develop:

  • preventive measures
  • improved diagnostic tools for early detection
  • better and longer-lasting treatments
  • curative treatments

Recently research developments includeTrusted Source:

Scientists are investigating a variety of factors that might influence the development of dementia, including:

  • genetic factors
  • various neurotransmitters
  • inflammation
  • factors that influence programmed cell death in the brain
  • tau protein (a protein found in neurons of the central nervous system)
  • oxidative stress (chemical reactions that can damage proteins, DNA, and lipids inside cells)

This research can help doctors and scientists better understand what causes dementia and discover how best to treat and possibly prevent the condition.

Currently, the Centers for Disease Control and Prevention (CDC) reports that Alzheimer’s disease is the seventh most commonTrusted Source cause of death in the United States. However, people may progress through the stages of dementia at varying speeds and experience different symptoms.

There’s currently no cure for dementia, but plenty of research is ongoing. The outlook for people with dementia may improve in the future.

If you or a loved one is experiencing memory issues or any other symptoms that point to dementia, consult a doctor as soon as possible. Early diagnosis can help people with dementia and their families plan for the future.