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

Written by the Healthline Editorial Team | Published on August 23, 2013
Medically Reviewed by George T. Krucik, MD, MBA on August 23, 2013

Dementia and Alzheimer's disease are often confused. Learn how they differ from each other and in what similarities they share.

The Dementia/Alzheimer’s Connection

Many people use the words “dementia” and “Alzheimer’s disease” interchangeably. However, they’re not the same thing. You can have a form of dementia that is completely unrelated to Alzheimer’s disease.

Although younger people can develop dementia and/or Alzheimer’s disease, your risk increases as you age. Still, neither is considered a normal part of growing older.

Dementia Is a Group of Symptoms

Dementia isn’t a disease. It’s a group of symptoms that affect mental tasks like memory and reasoning. Dementia can be caused by a variety of conditions, the most common of which is Alzheimer’s disease.

As dementia progresses, it can have a devastating impact on the ability to function independently. It’s a major cause of disability for older people, and places an emotional and financial burden on families and caregivers.

The World Health Organization (WHO) says that 35.6 million people around the world are living with dementia.

Signs of Dementia

Early symptoms of dementia can be mild and easily overlooked. It often begins with simple episodes of forgetfulness. People with dementia have trouble keeping track of time and tend to lose their way in familiar settings.

As dementia progresses, forgetfulness and confusion grow. It becomes harder to recall names and faces. Personal care becomes a problem. Obvious signs of dementia include repetitious questioning, inadequate hygiene, and poor decision-making.

In the most advanced stage, dementia patients become unable to care for themselves. Time, place, and people become more confusing. Behavior continues to change and can turn into depression and aggression.

Causes of Dementia

Dementia is a problem of the brain that you’re more likely to develop as you age. Many conditions can cause dementia, including degenerative diseases like Alzheimer’s, Parkinson’s, and Huntington’s. According to the Cleveland Clinic, Alzheimer’s disease is responsible for 50 to 70 percent of all cases of dementia.

Infections such as HIV can trigger dementia. So can vascular diseases and stroke. Depression and chronic drug use are other possible causes.

Alzheimer’s Is a Disease

Alzheimer’s is a progressive disease of the brain that slowly impairs memory and cognitive function. The exact cause is unknown and there is no cure.

The National Institutes of Health (NIH) estimate that more than five million people in the United States have Alzheimer’s disease. Although younger people can (and do) get Alzheimer’s, symptoms generally begin after age 60.

The time from diagnosis to death can be as little as three years in people over 80 years old. However, it can be much longer for younger people.

The Alzheimer’s Brain

Damage to the brain begins years before symptoms show. Abnormal protein deposits form plaques and tangles in the brain of someone with Alzheimer’s disease. Connections between cells are lost and they begin to die. In advanced cases, the brain shows significant shrinkage.

It’s impossible to diagnose Alzheimer’s with 100 percent accuracy while a person is alive. The diagnosis can only be confirmed during an autopsy, when the brain is examined under a microscope. However, specialists are able to make the correct diagnosis up to 90 percent of the time, according to the NIH.

Treating Dementia

In some cases, treating the condition that causes dementia may help. Conditions most likely to respond to treatment include dementia caused by drugs, tumors, metabolic disorders, and hypoglycemia.

In most cases, dementia cannot be reversed. However, many forms are treatable. The right medication can help manage dementia, including dementia due to Alzheimer’s disease.

Dementia patients can also benefit from supportive services from home health aids and other caregivers. An assisted living facility or nursing home may be necessary as the disease progresses.

Find the Best Medications for Alzheimer's Disease »

Mixed Dementia

Dementia consists of a set of symptoms that can be indicative of more than one underlying condition. Often, patients are found to have multiple conditions that may contribute to dementia. (Although a diagnosis of mixed dementia can only be confirmed upon autopsy.)

Many of these people are thought to have both vascular dementia and Alzheimer’s disease. Mixed dementia may become more common as our lifespans increase.

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