What’s the Difference Between Dementia and Alzheimer’s?

Dementia includes conditions that cause memory loss, confusion, personality changes, and a decline in self-care abilities. Alzheimer’s disease is the most common cause of dementia, and there are also other causes, such as frontotemporal dementia and vascular dementia.

A key feature of all types of dementia is that they cause gradually worsening effects. Some differences between different types of dementia are the speed of progression, and which of the symptoms are most significant,

A caregiver works with an older person in their kitchen

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How to Tell If It’s Dementia

Dementia causes progressively worsening symptoms affecting personality, cognition (mental process of gaining knowledge and understanding through thought, experience, and the senses), daily life skills, and emotions. Sometimes, people may recognize their own early signs of dementia, but most people lose that type of insight as the disease progresses. 

One of the defining characteristics of dementia is that it is a gradual loss of thinking abilities, self-control, and independence. Usually, dementia begins after age 50, but in rare cases, early-onset dementia may begin earlier in adulthood.

Since different types of dementia share similar symptoms, your specific diagnosis may take time. Some features that can help distinguish one type from another include associated symptoms, such as emotional changes or challenges with movement.

Alzheimer’s Is the Most Common Type of Dementia

Alzheimer’s disease is the most common type of dementia. According to the Centers for Disease Control and Prevention (CDC), 6.9 million people in the United States had this condition in 2020, and it is the seventh leading cause of death among U.S. adults. Alzheimer’s disease is more common with advancing age, typically affecting people aged 65 or older.

Alzheimer’s disease symptoms can include:

  • Being suspicious of others
  • Decreased appetite and a preference for certain foods
  • Difficulty with responsibilities that require decision-making and concentration, such as keeping track of finances
  • Getting lost
  • Inability to keep up with conversations 
  • Losing the ability to take care of daily tasks, such as cooking or laundry
  • Loss of motivation
  • Memory loss
  • Personality changes
  • Repeating yourself or asking the same question, even after you’ve heard the answer
  • Sleeping more than usual

Many people who develop Alzheimer’s disease have a major personality change. For example, being suspicious or not being motivated can be very different personality traits compared to how a person used to be before Alzheimer’s disease. These changes can often be upsetting for loved ones and may be the reason they seek a healthcare provider’s evaluation.

Dementia Symptoms Can Be Slightly Unpredictable

The symptoms of dementia often follow a pattern, with mild short-term memory loss and difficulty with complex decision-making as early symptoms. Later, more obvious symptoms may develop, such as getting lost, lack of inhibition, or inability to do things that you used to do—such as cooking a familiar recipe or personal grooming. Eventually, a lack of motivation and loss of appetite are common.

However, sometimes the sequence of symptoms may differ from one person to another and may not follow the predicted timing or progression that’s characteristic of the disease. Reasons for these variations can involve personal differences, mixed dementia, or underlying health conditions.

Dementia Is Progressive

One of the defining characteristics of dementia is that it is progressive. Dementia is a loss of cognitive abilities that a person already has. 

Most types of dementia gradually worsen over the months and years after the initial symptoms start, but some types worsen more quickly than others. For example, Alzheimer’s disease, vascular dementia, Lewy body disease, and frontotemporal dementia may progress over several years, while Huntington’s disease and Creutzfeldt-Jakob disease (CJD) worsen rapidly.

Usually, dementia increases the risk of death because the loss of self-care and reasoning abilities can lead to serious health problems or injuries. However, some people may survive for a decade or longer after diagnosis, especially if they don’t have other underlying health problems, such as heart disease or cancer.

Some Symptoms of Dementia May Improve With Early Treatment

Some symptoms of dementia and some types of dementia are more treatable than others. Generally, dementia is caused by conditions that are not reversible, but a few types can be treated to slow disease progression or prevent health complications.

Some vitamin deficiencies, including vitamin B12 deficiency and thiamine deficiency, have been associated with symptoms of dementia. Chronic alcohol overuse can lead to dementia and also increases the risk of thiamine deficiency. These types of dementia are sometimes considered partially reversible because some symptoms may improve with nutritional supplementation.

You May Be Able to Reduce Your Risk

You can reduce your risk of some types of dementia. Evidence shows that lifestyle strategies can decrease the risk of vascular dementia and Alzheimer’s disease. Additionally, dementia associated with alcohol use or nutritional deficiencies can be prevented through diet, lifestyle measures, or nutritional supplementation if needed.

Key components of preventing dementia include:

  • Getting enough sleep
  • Getting treatment for hypertension (high blood pressure)
  • Getting treatment for unhealthy blood levels of triglyceride and cholesterol
  • Maintaining a healthy weight
  • Managing stress
  • Managing your blood sugar if you have diabetes
  • Staying active

Overall, taking care of your health can help delay the onset or progression of dementia and can reduce the impact that dementia has on your life. Health problems such as hypertension and diabetes can lead to stroke, increasing the likelihood of dementia.

Additionally, stress and lack of sleep have been shown to lead to oxidative stress, which can harm your body, including your brain, and may increase the risk of dementia. Oxidative stress occurs when the unstable molecules produced by cell processes (known as free radicals) outstrip the ability of antioxidants to neutralize them.

Other Types and Causes of Dementia

Alzheimer's disease is associated with the gradual shrinking of cells in the hippocampus, an area of the brain involved in memory. The other types of dementia are caused by damage to different brain regions.

Vascular Dementia

Vascular dementia is a loss of cognitive abilities due to stroke-induced brain damage. Untreated hypertension, uncontrolled diabetes, high cholesterol, and heart disease increase the risk of having small strokes affecting different areas of the brain.

Having more than one small stroke can have an impact on memory, reasoning, emotional control, and daily functioning. Usually, a large stroke causes weakness or vision changes on one side of the body. Sometimes, small strokes do not cause these obvious physical symptoms, so they can be “silent” with unnoticed effects. In these cases, dementia can come on gradually.

Dementia With Lewy Bodies

Dementia with Lewy bodies, a disease that is similar to Parkinson’s disease, causes progressively worsening memory loss, difficulty with thinking skills, behavioral changes, highly expressive moods, and movement symptoms similar to those of Parkinson’s disease.

Lewy body dementia is associated with a buildup of substances called Lewy bodies in the brain.

Frontotemporal Dementia (FTD)

Frontotemporal dementia is a degeneration of nerves in the frontal and temporal (at the sides of the brain) regions of the brain. This condition causes a rapid decline in thinking skills and self-control. Symptoms may include taking things that don’t belong to you, such as someone else’s food, difficulty maintaining a normal sleep schedule, changes in appetite, or saying things that are completely out of character. 

Creutzfeldt-Jakob Disease

A rare condition, CJD, occurs due to a protein-like particle, called a prion, in the brain. It may be transmitted through contamination of nerve tissue. Some cases have been reported after transplants of nerve tissue in the brain. 

Huntington’s Disease

Huntington’s disease is a hereditary condition that causes dementia and a movement disorder, often beginning in early to mid-adulthood—typically in the 30s and 40s. Huntington’s disease is fatal, and people tend to survive for less than 10 years after diagnosis.

This disease is inherited through an autosomal dominant pattern, which means that any person who inherits just one Huntington’s disease gene from one parent will develop the disease. The gene is not on the X or Y chromosome, so there is no difference in occurrence between people of any sex.

Normal Pressure Hydrocephalus

Normal pressure hydrocephalus is one of the partially treatable causes of dementia. This condition develops when there is atrophy (shrinking and cell death) of certain regions in the brain. This leads to hydrocephalus, which is a buildup of fluid in the ventricles (spaces) of the brain.

Normally, cerebrospinal fluid flows in the brain’s ventricles, but with normal pressure hydrocephalus, there is too much fluid. Symptoms include memory loss, decreased social inhibition, and difficulty walking.

Sometimes, normal pressure hydrocephalus develops as a result of brain tissue loss due to stroke, and it can also develop as a result of alcohol overuse or chronic diseases. Some neurodegenerative disorders, such as Parkinson’s disease, may predispose you to normal pressure hydrocephalus as well.

Removal of excess cerebrospinal fluid with an interventional procedure may help relieve hydrocephalus, potentially reducing some of the symptoms of this condition.

Mixed Dementia

It’s not uncommon to have mixed dementia with advancing age. Alzheimer’s disease and vascular dementia are both fairly common and may occur together. Additionally, a person may have Alzheimer’s disease or vascular dementia, along with another type of dementia, such as normal pressure hydrocephalus, dementia with Lewy bodies, or frontotemporal dementia.

It is unusual to have CJD or Huntington’s disease with another type of dementia because these two types of dementia are very rare and progress rapidly—usually leading to death before a person can develop another type of dementia

When to Contact a Healthcare Provider

If you or a loved one is having problems with your memory, concentration, mood, or thinking and decision-making skills, it’s important to see a healthcare provider.

Along with taking personal and family medical history and performing physical examination, your provider may give you a screening test to identify signs of dementia, a mood disorder, or a sleep disorder—which all can potentially cause these symptoms. Treatment then can help prevent worsening of your underlying cause.

If you or a loved one has already been diagnosed with dementia, see a healthcare provider for any of the following symptoms:

  • Agitation
  • Crying, distress, or signs of pain
  • Excessive sleeping
  • Fever
  • Incontinence (loss of bladder or bowel control)
  • Worsening changes in appetite

Some of these symptoms could be an indication that dementia is worsening but also could be an indication that there’s an underlying treatable problem.

For example, a urinary tract infection may cause incontinence (involuntary leakage). Infections or other illnesses can be dangerous for a person who has dementia, and treatment can help improve the illness and help slow dementia progression.

Summary

Alzheimer’s disease is the most common type of dementia, but there are other types as well. It’s also common for people to have mixed dementia, which involves two or more types of dementia.

Symptoms of the different types of dementia often overlap, but some people and some types of dementia are more likely to involve personality changes, while others are more likely to involve problems with self-care.

Getting the right diagnosis and starting treatment can improve the quality of life and survival for people with dementia. Additionally, it’s important to have the right diagnosis so you and your loved ones can understand what to expect and make adjustments to have the best possible outcome. 

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Verywell Health 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.
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Heidi Moawad, MD

By Heidi Moawad, MD
Dr. Moawad is a neurologist and expert in brain health. She regularly writes and edits health content for medical books and publications.