The Facts About Alzheimer’s Disease

The Alzheimer's Handbook for Caregivers


What Is Alzheimer’s Disease?

Alzheimer’s (AHLZ-high-merz) disease is a progressive brain disorder that gradually destroys a person’s memory and ability to learn, reason, make judgments, communicate, and carry out daily activities. As Alzheimer’s progresses, individuals may also experience changes in personality and behavior, such as anxiety, suspiciousness or agitation, as well as delusions or hallucinations.

Although there is currently no cure for Alzheimer’s, new treatments are on the horizon as a result of accelerating insight into the biology of the disease. Research has also shown that effective care and support can improve quality of life for individuals and their caregivers over the course of the disease, from diagnosis to the end of life.

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Alzheimer’s vs. Dementia: Is Alzheimer’s a Type of Dementia?

Alzheimer’s is the most common form of dementia, a group of conditions that all gradually destroy brain cells and lead to progressive decline in mental function. Vascular dementia, another common form, results from reduced blood flow to the brain’s nerve cells. In some cases, Alzheimer’s disease and vascular dementia can occur together in a condition called “mixed dementia.” Other causes of dementia include frontotemporal dementia, dementia with Lewy bodies, Creutzfeldt-Jakob disease, and Parkinson’s disease.

What Causes Alzheimer’s Disease?

Alzheimer’s disease has no known single cause, but in the last 15 years scientists have learned a great deal about factors that may play a role. Scientists studying the biology of Alzheimer’s disease believe that whatever triggers the disease begins to damage the brain years before symptoms appear. When symptoms emerge, nerve cells that process, store, and retrieve information have already begun to degenerate and die.

Scientists regard two abnormal microscopic structures called “plaques” and “tangles” as Alzheimer hallmarks. Amyloid plaques (AM-uh-loyd plaks) are clumps of protein that accumulate outside the brain’s nerve cells. Tangles are twisted strands of another protein that form inside cells. Scientists do not yet know whether plaques or tangles cause Alzheimer’s or are a byproduct of some other process. Clinical trials of experimental drugs targeting amyloid are under way and should help clarify the role plaques play.

What Are the Risk Factors of Alzheimer’s Disease?

Scientists have learned that Alzheimer’s disease involves the malfunction or death of nerve cells, but why this happens is still not known. However, they have identified certain risk factors that increase the likelihood of developing Alzheimer’s and discovered clues about possible strategies to reduce risk.

  • Age: The greatest known risk factor is increasing age, and most individuals with the illness are 65 and older. The likelihood of developing Alzheimer’s approximately doubles every five years after age 65. After age 85, the risk reaches nearly 50 percent.
  • Family History: Research has shown that those who have a parent or sibling with Alzheimer’s are two to three times more likely to develop the disease than those who do not. The more individuals in a family who have the illness, the greater the risk.
  • Genetics: Scientists have so far identified one gene that increases risk of Alzheimer’s but does not guarantee an individual will develop the disorder. Research has also revealed certain rare genes that virtually guarantee an individual will develop Alzheimer’s. The genes that directly cause the disease have been found in only a few hundred extended families worldwide and are thought to account for a tiny percentage of cases. Experts believe the vast majority of cases are caused by a complex combination of genetic and non-genetic influences.
  • Environment: Age, family history, and genetics are all risk factors we can’t change. Scientists worldwide are looking for other risk factors that may provide opportunities for treatment or prevention. Some of our best information about the relative importance of risk factors we can and can’t control comes from studies of identical twins, who are the same age and have the same genes but have different life experiences. Several twin studies have shown that when one twin develops Alzheimer’s, the other twin is at increased risk but does not always develop the disease. Other studies suggest that even in cases where both twins develop Alzheimer’s, the age where symptoms appear can differ significantly. These results suggest that even when there is a strong genetic influence, other factors can play a major role.
  • Head Injury: Research is beginning to reveal clues about some potentially controllable risk factors. There appears to be a strong link between serious head injury and future risk of Alzheimer’s. It’s important to protect your head by buckling up your seat belt, wearing your helmet and fall-proofing your home.
  • Overall Brain Health: One promising line of research suggests that strategies for overall healthy aging may help keep the brain healthy and may even offer some protection against Alzheimer’s. These measures include eating a healthy diet, staying socially active, avoiding tobacco and excess alcohol, and exercising both body and mind.

Heart/Head Connection: Some of the strongest evidence links brain health to heart health. The risk of developing Alzheimer’s or vascular dementia appears to be increased by many conditions that damage the heart and blood vessels, including heart disease, diabetes, stroke and high blood pressure or cholesterol. You should work with your doctor to monitor your heart health and treat any problems that arise. Autopsy studies provide additional evidence for the heart-head connection. These studies suggest that plaques and tangles are more likely to cause Alzheimer symptoms if strokes or damage to the brain’s blood vessels are also present.

Getting a Diagnosis for Alzheimer’s Disease

A physician should be consulted about concerns with memory, thinking skills, and changes in behavior. For people with dementia and their families, an early diagnosis has many advantages:

  • Time to make choices that maximize quality of life
  • Lessened anxieties about unknown problems
  • A better chance of benefiting from treatment
  • More time to plan for the future

It is also important for a physician to determine the cause of memory loss or other symptoms. Some dementia-like symptoms can be reversed if they are caused by treatable conditions, such as depression, drug interaction, thyroid problems, excess use of alcohol, or certain vitamin deficiencies.

What Are the Common Tests for an Alzheimer’s Diagnosis?

There is no one diagnostic test that can detect if a person has Alzheimer’s disease. The process involves several kinds of tests and may take more than one day. Diagnostic tools and criteria make it possible for physicians to make a diagnosis of Alzheimer’s with an accuracy of about 90 percent.

Evaluations may include the following steps:

  • Consultation with a primary care physician and possibly a neurologist or other specialists
  • A medical history, which collects information about current mental or physical conditions, prescription and nonprescription drug use, and family health history
  • A mental status evaluation to assess sense of time and place; ability to remember, understand, and communicate; and ability to do simple math problems
  • A series of evaluations that test memory, reasoning, vision-motor coordination, and language skills
  • A physical examination, which includes the evaluation of the person’s nutritional status, blood pressure, and pulse
  • An examination that tests sensation, balance, and other functions of the nervous system
  • A brain scan to detect other causes of dementia such as stroke
  • Laboratory tests, such as blood and urine tests, to provide additional information about problems other than Alzheimer’s that may be causing dementia
  • A psychiatric evaluation, which provides an assessment of mood and other emotional factors that could cause dementia-like symptoms or may accompany Alzheimer’s disease

Understanding an Alzheimer’s Diagnosis

A diagnosis of Alzheimer’s usually falls into one of the two categories: probable Alzheimer’s or possible Alzheimer’s.

What Is a Diagnosis of Probable Alzheimer’s?

A diagnosis of probable Alzheimer’s indicates that the physician has ruled out all other disorders that may be causing dementia and has come to the conclusion that symptoms are most likely the result of Alzheimer’s disease.

What Is a Diagnosis of Possible Alzheimer’s?

A diagnosis of possible Alzheimer’s means that Alzheimer’s disease is probably the primary cause of dementia but that another disorder may be affecting the progression of symptoms.

It is important that you discuss the diagnosis with your physician. Some questions to ask:

  • What does the diagnosis mean?
  • Are additional tests needed to confirm the diagnosis?
  • What changes in behavior or mental capacity can be expected over time?
  • What care will be needed, and what treatment is available?
  • What else can be done to alleviate symptoms?
  • Are there clinical trials being conducted in my area?

What Are the Treatment Options for Alzheimer’s?

There is no cure for Alzheimer’s disease. However, there are several drug treatments that may improve or stabilize symptoms and several care strategies and activities that may minimize or prevent behavioral problems. Researchers continue to look for new treatments to alter the course of the disease and other strategies to improve the quality of life for people with dementia.

Prescription Drugs

There are numerous prescription drugs on the market. You must consult with the treating physician, follow their advice, and take the drugs prescribed by the physician.

Herbal Treatment

Do not self-administer these over-the-counter products without discussing with your physician.

Behavioral and Psychiatric Symptoms of Alzheimer’s

When Alzheimer’s disrupts memory, language, thinking and reasoning, these effects are referred to as “cognitive symptoms” of the disease. The term “behavioral and psychiatric symptoms” describes a large group of additional symptoms that occur to at least some degree in many individuals with Alzheimer’s.

In early stages of the disease, people may experience personality changes such as irritability, anxiety or depression. In later stages, other symptoms may occur, including: sleep disturbances; agitation (physical or verbal aggression, general emotional distress, restlessness, pacing, shredding paper or tissues, yelling); delusions (firmly held belief in things that are not real); or hallucinations (seeing, hearing or feeling things that are not there).

Many individuals with Alzheimer’s and their families find behavioral and psychiatric symptoms to be the most challenging and distressing effects of the disease. These symptoms are often a determining factor in a family’s decision to place a loved one in residential care. They also often have an enormous impact on care and quality of life for individuals living in long-term care facilities.

Medical Evaluation for Psychiatric Symptoms of Alzheimer’s

A person exhibiting behavioral and psychiatric symptoms should receive a thorough medical evaluation, especially when symptoms come on suddenly. Treatment depends on a careful diagnosis, determination of the possible causes, and the types of behavior the person is experiencing. With proper treatment and intervention, significant reduction or stabilization of the symptoms can often be achieved.

Symptoms often reflect an underlying infection or medical illness. For example, the pain or discomfort caused by pneumonia or a urinary tract infection can result in agitation. An untreated ear or sinus infection can cause dizziness and pain that affect behaviors. Side effects of prescription medication are another common contributing factor to behavioral symptoms. Side effects are especially likely to occur when individuals are taking multiple medications for several health conditions, creating a potential for drug interactions.

Non-Drug Interventions for Agitation Caused by Dementia

There are two distinct types of treatments for agitation: non-drug interventions and prescription medications. Non-drug interventions should be tried first. In general, steps to managing agitation include (1) identifying the behavior, (2) understanding its cause, and (3) adapting the caregiving environment to remedy the situation.

Correctly identifying what has triggered symptoms can often help in selecting the best environment. Causes of agitation may include:

  • Change in caregiver
  • Change in living arrangements
  • Travel
  • Hospitalization
  • Presence of houseguests
  • Bathing
  • Being asked to change clothing

A key principle of intervention is redirecting the affected individual’s attention, rather than arguing, disagreeing, or being confrontational with the person. Additional intervention strategies include the following:

  • Simplify the environment
  • Simplify tasks and routines
  • Allow adequate rest between stimulating events
  • Use labels to cue or remind the person
  • Equip doors and gates with safety locks
  • Remove guns
  • Use lighting to reduce confusion and restlessness at night

Medications to Treat Agitation Caused by Alzheimer’s

Medications can be effective in the management of some symptoms of agitation, but they must be used carefully and are most effective when combined with behavioral or environmental changes. Medications should target specific symptoms so that improvement can be monitored. People with Alzheimer’s disease are susceptible to serious side effects that require close observation. In general, it is best to begin treatment with a single medication and with low doses.

Alternative Treatments for Alzheimer’s

Several herbal remedies and other dietary supplements are promoted as effective treatments for Alzheimer’s disease and related disorders. Claims about the safety and effectiveness of these products, however, are based largely on testimonials, tradition, and a rather small body of scientific research. The rigorous scientific research required by the U.S. Food and Drug Administration for the approval of a prescription drug is not required by law for the marketing of dietary supplements.

Concerns About Alternative Therapies for Alzheimer’s

Although many of these remedies may be valid candidates for treatments, there are legitimate concerns about using these drugs as an alternative or in addition to physician-prescribed therapy:

  • Effectiveness and safety are unknown. The maker of a dietary supplement is not required to provide the U.S. Food and Drug Administration (FDA) with the evidence on which it bases its claims for safety and effectiveness.
  • Purity is unknown. The FDA has no authority over supplement production. It is a manufacturer’s responsibility to develop and enforce its own guidelines for ensuring that its products are safe and contain the ingredients listed on the label in the specified amounts.
  • Bad reactions are not routinely monitored. Manufacturers are not required to report to the FDA any problems that consumers experience after taking their products. The agency does provide voluntary reporting channels for manufacturers, health care professionals, and consumers, and will issue warnings about products when there is cause for concern.

Dietary supplements can have serious interactions with prescribed medications. No supplement should be taken without first consulting a physician.

Dispelling Myths About Alzheimer’s

Is memory loss a natural part of aging?

In the past people believed memory loss was a normal part of aging, often regarding even Alzheimer’s as natural age-related decline. Experts now recognize severe memory loss as a symptom of serious illness. Whether memory naturally declines to some extent remains an open question. Many people feel that their memory becomes less sharp as they grow older, but determining whether there is any scientific basis for this belief is a research challenge still being addressed.

Is Alzheimer’s disease not fatal?

Alzheimer’s is a fatal disease. It begins with the destruction of cells in regions of the brain that are important for memory. However, the eventual loss of cells in other regions of the brain leads to the failure of other essential systems in the body. Also, because many people with Alzheimer’s have other illnesses common in older age, the actual cause of death may be no single factor.

Does drinking out of aluminum cans or cooking in aluminum pots and pans cause Alzheimer’s disease?

Based on current research, getting rid of aluminum cans, pots, and pans will not protect you from Alzheimer’s disease. The exact role (if any) of aluminum in Alzheimer’s disease is still being researched and debated. However, most researchers believe that not enough evidence exists to consider aluminum a risk factor for Alzheimer’s or a cause of dementia.

Does aspartame cause memory loss?

Several studies have been conducted on aspartame’s effect on cognitive function in both animals and humans. These studies found no scientific evidence of a link between aspartame and memory loss. Aspartame was approved by the U.S. Food and Drug Administration (FDA) in 1996 for use in all foods and beverages. The sweetener, marketed as Nutrasweet® and Equal®, is made by joining two protein components, aspartic acid and phenylalanine, with 10 percent methanol. Methanol is widely found in fruits, vegetables and other plant foods.

Is there a way to stop the progression of Alzheimer’s disease?

At this time, there is no medical treatment to cure or stop the progression of Alzheimer’s disease. FDA-approved drugs may temporarily improve or stabilize memory and thinking skills in some individuals.

Statistics About Alzheimer’s Disease

Alzheimer’s disease is not a normal part of aging. It is a devastating disorder of the brain’s nerve cells that impairs memory, thinking, and behavior and leads, ultimately, to death. The impact of Alzheimer’s on individuals, families and our health care system makes the disease one of our nation’s greatest medical, social, and economic challenges.

  • An estimated 4.5 million Americans have Alzheimer’s disease. The number of Americans with Alzheimer’s has more than doubled since 1980. 1
  • The number of Americans with Alzheimer’s disease will continue to grow – by 2050 the number of individuals with Alzheimer’s could range from 11.3 million to 16 million. 1
  • Finding a treatment that could delay onset by five years could reduce the number of individuals with Alzheimer’s disease by nearly 50 percent after 50 years.2
  • In a Gallup poll commissioned by the Alzheimer’s Association, 1 in 10 Americans said that they had a family member with Alzheimer’s and 1 in 3 knew someone with the disease. 3
  • Increasing age is the greatest risk factor for Alzheimer’s. One in 10 individuals over 65 and nearly half of those over 85 are affected.4 Rare, inherited forms of Alzheimer’s disease can strike individuals as early as their 30s and 40s. 5
  • A person with Alzheimer’s disease will live an average of eight years and as many as 20 years or more from the onset of symptoms as estimated by relatives.6 From the time of diagnosis, people with Alzheimer’s disease survive about half as long as those of similar age without dementia. Average survival time is affected by age at diagnosis and severity of other medical conditions. 7
  • National direct and indirect annual costs of caring for individuals with Alzheimer’s disease are at least $100 billion, according to estimates used by the Alzheimer’s Association and the National Institute on Aging. 8
  • Alzheimer’s disease costs American business $61 billion a year, according to a report commissioned by the Alzheimer’s Association. Of that figure, $24.6 billion covers Alzheimer health care and $36.5 billion covers costs related to caregivers of individuals with Alzheimer’s, including lost productivity, absenteeism and worker replacement. 9
  • More than 7 out of 10 people with Alzheimer’s disease live at home, where almost 75 percent of their care is provided by family and friends.6 The remainder is “paid” care costing an average of $19,000 per year. Families pay almost all of that out of pocket. 15
  • Half of all nursing home residents have Alzheimer’s disease or a related disorder. 11
  • The average cost for nursing home care is $42,000 per year10 but can exceed $70,000 per year in some areas of the country. 12
  • The average lifetime cost of care for an individual with Alzheimer’s is $174,000. 8
  • Medicare costs for beneficiaries with Alzheimer’s are expected to increase 75 percent, from $91 billion in 2005 to $160 billion in 2010; Medicaid expenditures on residential dementia care will increase 14 percent, from $21 billion in 2005 to $24 billion in 2010, according to a report commissioned by the Alzheimer’s Association. 13
  • The Alzheimer’s Association has awarded more than $165 million in research grants since 1982, according to our audited annual financial statements.
  • The federal government estimates spending approximately $647 million for Alzheimer’s disease research in fiscal year 2005. 14


For questions or further information on statistics, please contact the Alzheimer’s Association Benjamin B. Green-Field Library and Resources by calling 1.800.272.3900 or 1.312.335.9602 or by emailing

  1. Hebert, LE; Scherr, PA; Bienias, JL; Bennett, DA; Evans, DA. “Alzheimer Disease in the U.S. Population: Prevalence Estimates Using the 2000 Census.” Archives of Neurology August 2003; 60 (8): 1119 – 1122.
  2. Brookmeyer, R; Gray, S; Kawas, C. “Projections of Alzheimer’s Disease in the United States and the Public Health Impact of Delaying Disease Onset.” American Journal of Public Health 1998; 88(9): 1337 – 1342.
  3. 1992 Gallup survey of 1,015 individuals. For more information, please contact our Green-Field Library.
  4. Evans, DA; Funkenstein, HH; Albert, MS; et al. “Prevalence of Alzheimer’s Disease in a Community Population of Older Persons: Higher than Previously Reported.” JAMA 1989; 262(18): 2552 – 2556.
  5. Bird, TD; Sumi, SM; Nemens, EJ; Nochlin, D; Schellenberg, G; et al. “Phenotypic Heterogeneity in Familial Alzheimer’s Disease: A Study of 24 Kindreds.” Annals of Neurology 1989; 25(1): 12 – 25.
  6. Losing a Million Minds: Confronting the Tragedy of Alzheimer’s Disease and Other Dementias. U.S. Congress Office of Technology Assessment; U.S. Government Printing Office, 1987; p. 14.
  7. Larson, EB, Shadlen, M-F, et al. “Survival after Initial Diagnosis of Alzheimer Disease.” Annals of Internal Medicine, 6 April 2004; pp. 501 – 509.
  8. Ernst, RL; Hay, JW. “The U.S. Economic and Social Costs of Alzheimer’s Disease Revisited.” American Journal of Public Health 1994; 84(8): 1261 – 1264. For the $100 billion annual cost, this study cites figures based on 1991 data, which were updated in the journal’s press release to 1994 figures. Cited in 2001 – 2002 Alzheimer’s Disease Progress Report. National Institutes of Health publication number 03-5333, July 2003; p. 2.
  9. Koppel, R. Alzheimer’s Disease: The Costs to U.S. Businesses in 2002. Washington, D.C.: Alzheimer’s Association; 2002.
  10. Rice, DP; et al. “The Economic Burden of Alzheimer’s Disease.” Health Affairs, Summer 1993; 12(2): 164 – 176.
  11. National Nursing Home Survey. National Center for Health Statistics, 1985; p. 49.
  12. Unpublished data reported by Alzheimer’s Association chapters in some regions.
  13. Saving Lives, Saving Money: Dividends for Americans Investing in Alzheimer Research. A report from the Lewin Group, commissioned by the Alzheimer’s Association. Washington, D.C.: 2004.
  14. Unpublished analysis of federal budget documents by Alzheimer’s Association senior public policy staff.
  15. Fox, PJ; Kohatsu, N; et al. “Estimating Costs of Caring for People with Alzheimer’s Disease in California: 2000 – 2040.” Journal of Public Health Policy 2001; 22(1): 88 – 97.