The Basics of Alzheimer's Disease

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Known by many as "the long goodbye," Alzheimer's disease is increasing at an alarming rate in the United States. An estimated 5 million people in the United States are now living with Alzheimer's, and someone is diagnosed with the disease every 72 seconds.

Most people with Alzheimer's are age 65 or older, but at least 200,000 people under the age of 65 are also living with an early-onset form of the disease. By the year 2030, the number of individuals with Alzheimer's could approach 8 million; if scientists can't find a way to cure or prevent Alzheimer's, this number could range between 11 million and 16 million by the year 2050.

Alzheimer's vs. Dementia

Alzheimer's disease is a progressive, degenerative disease of the brain that results in dementia. The terms Alzheimer's and dementia are often used interchangeably, but there's a distinct difference between them.

Dementia is a broader term than Alzheimer's and refers to any brain syndrome resulting in problems with memory, orientation, judgment, executive functioning, and communication.

Other Causes of Dementia

Alzheimer's disease is the most common form of dementia. According to the Alzheimer's Association, 60% to 70% of dementia cases are due to Alzheimer's. However, many other diseases can cause dementia, such as stroke, Parkinson's disease, and Wernicke-Korsakoff syndrome. Some infectious diseases can also result in dementia, such as HIV or the extremely rare Creutzfeldt-Jakob disease.

When individuals are diagnosed with mixed dementia, more than one disease process is causing the dementia. For example, a person might have dementia due to both Alzheimer's and a stroke.

Reversible Conditions That Resemble Alzheimer's

Sometimes symptoms that look like Alzheimer's are actually due to a reversible medical condition, such as depression or delirium. These conditions aren't types of dementia; they're reversible problems that mimic Alzheimer's disease and other dementias.


People with Alzheimer's exhibit different symptoms as the disease progresses, but most symptoms are either cognitive or behavioral.


No single test can prove that a person has Alzheimer's disease, although imaging technology is rapidly becoming more precise. Still, according to the Alzheimer's Association, experts estimate that a comprehensive evaluation by a skilled physician can pinpoint the cause of Alzheimer's-like symptoms with over 90% accuracy.


There is currently no cure for Alzheimer's, but several drug and non-drug treatments are available. Cognitive symptoms are treated with one or more of the four FDA-approved prescription medications for Alzheimer's disease. Behavioral symptoms are sometimes treated with medications, but non-drug approaches, such as behavior management, are often just as successful.

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Article Sources

  • Alzheimer’s disease facts and figures. Alzheimer's Association. 2007.

  • Basics of Alzheimer’s disease: What it is and what you can do. Alzheimer's Association. 2005.

  • Journey to discovery: 2005-2006 progress report on Alzheimer’s disease. National Institutes of Health. 2007.