Alzheimer's disease: The most common form of dementia

By Jean Cherry, RN, MBA Sep 21, 2021 • 10 min.


What is Alzheimer's? Alois Alzheimer, a German psychiatrist, completed extensive work linking certain symptoms to specific brain changes, which later became known as Alzheimer's disease.

Alzheimer's disease is a progressive disease causing memory loss and cognitive difficulties that make it hard to carry out daily activities.

What is the difference between dementia and Alzheimer's?

Understanding dementia vs. Alzheimer's can be confusing, as many symptoms may overlap. In fact, there is a difference between dementia and Alzheimer's. Dementia describes a group of symptoms or syndrome involving memory loss, decreased ability to complete daily activities and problems with communicating. Alzheimer's disease is the most common type of dementia, accounting for 60% to 80% of dementia cases.

Here are some Alzheimer's facts:

  • Approximately 5.7 million Americans are affected by Alzheimer's disease, and about 47 million people worldwide have the disease
  • Most people live with Alzheimer's for four to eight years, but you can live up to 20 years with the disease
  • Alzheimer's is the third leading cause of death, behind heart disease and cancer, in older people and the sixth leading cause of death overall
  • The cost of Alzheimer's in the U.S. has been estimated at $355 billion in 2021

What are the symptoms and stages of Alzheimer's?

There are three general Alzheimer's disease stages:

  • Mild or early stage
  • Moderate or middle stage
  • Severe or late stage

People can progress through the Alzheimer's stages experiencing symptoms differently.

Early signs of Alzheimer's consist of issues with memory that may at first be attributed to stress or other conflicting diagnoses and do not interfere with daily living. Early onset Alzheimer's can appear when people are in their 40s and 50s. Mild or early Alzheimer's symptoms include cognitive difficulties. People may wander and get lost, take longer to complete normal daily tasks, have impaired reasoning, repeat questions and exhibit other behavior changes. An Alzheimer's gene has been identified with early Alzheimer's and is associated with familial Alzheimer's disease. Moderate stage Alzheimer's symptoms include worsening memory loss and confusion, inability to learn things and difficulty coping with new situations. A person may even develop delusions, hallucinations or paranoia.

In severe or late-stage Alzheimer's, there is a loss in the ability to control movement, difficulty communicating and exhibiting profound personality changes. At this point, people may require Alzheimer's care around the clock.

What causes Alzheimer's?

Alzheimer's research has determined that the causes of Alzheimer's are a combination of genetics, lifestyle and environmental factors that develop over time, up to decades in the brain. The causes are not entirely understood, but the disease damages and kills brain cells, causing the brain to shrink. Specifically, abnormal plaques or beta-amyloid protein clumps interfere with cell communication. In addition, threads of tau protein tangle inside brain cells. This results in the failure of the brain's transport system.

Is there an Alzheimer's cure?

At this time, there is no cure for Alzheimer's disease.

People often ask, Is Alzheimer's genetic? Is Alzheimer's hereditary? The answer is yes, but genes account for only 1% of Alzheimer's cases. The two types of genes that can influence the development of Alzheimer's are risk genes and deterministic genes.

  • Risk genes, such as apolipoprotein E-e4 and APOE-e2 or APOE-e3, increase risk but don't guarantee you will get the disease.
  • Deterministic genes, including amyloid precursor protein, presenilin-1 and presenilin-2, will cause the disease. People with either risk or deterministic genes are more likely to develop early onset Alzheimer's.

Alzheimer's prevention

Since there are no cures for Alzheimer's, researchers are studying how to prevent Alzheimer's. Studies show that regular exercise, which increases blood and oxygen to the brain, is a beneficial strategy. Following a heart-healthy diet that limits sugar and saturated fats and includes more vegetables, fruits, low-fat dairy products and whole grains may also aid in Alzheimer's disease prevention.

Studies show that having strong social connections and keeping mentally active by learning new languages or taking courses at a local university or community education program help decrease cognitive decline. Head trauma has been linked to future risk of Alzheimer's, so wearing a seat belt, fall-proofing your home and wearing a helmet when playing sports can decrease risk.

What Alzheimer's testing is used for diagnosis?

There is no single test that can detect Alzheimer's. An Alzheimer's diagnosis is determined by completing a full medical assessment. Testing for Alzheimer's is comprised of a complete medical history, tests on mental status and mood, a physical exam, neurological testing and blood tests. Testing may also include brain imaging, such as computed tomography (CT), magnetic resonance imaging (MRI) or positron emission tomography (PET), to rule out various causes of dementia symptoms.

How is Alzheimer's treated?

Beginning Alzheimer's treatment early before the disease progresses can preserve functions of daily living for a time, give families time to plan for the future and allow opportunities for clinical trial participation with the newest treatments.

There is no one Alzheimer's drug that successfully treats Alzheimer's disease. Several Alzheimer's medication options are approved by the U.S. Food and Drug Administration (FDA) to treat mild to moderate symptoms. The most recent 2021 treatment is aducanumab for mild cognitive impairment. It can't restore memories, but it can remove amyloid plaques from the brain, slowing the progression of the disease. It must be infused intravenously monthly for over 45-60 minutes. There are also donepezil, rivastigmine and galantamine. Donepezil and memantine are FDA-approved to treat moderate to severe Alzheimer's symptoms. These treatments seem to only help some people with Alzheimer's, and they may only work for a limited time. Antipsychotics can help with behavioral symptoms to make life easier for people with Alzheimer's and their families.

Is there support for caregivers?

Caring for a person with Alzheimer's can be demanding, causing physical and emotional stress, as well as financial strain. Helping families understand the various stages and how to deal with personality changes and behavior can help.

  • Call the Alzheimer's Association helpline, available 24 hours a day: 800-272-3900.
  • Support groups, accessed both in person and online, can provide a way for caregivers to share experiences, talk about concerns, get tips on managing their loved one's condition and receive emotional support. Contact your local Alzheimer's Association.
  • Various organizations, such as the National Institute on Aging (NIA) Alzheimer's and Related Dementias Education and Referral (ADEAR) Center has staff available to answer the telephone, email and written requests. They can also refer caregivers to local and national resources for respite care and long-term care.
  • Caregivers may want to take advantage of their local adult day center to get a break each day and reduce their isolation by spending time with friends. Check out the Family Caregiver Alliance (FCA) for resources.
  • The Alzheimer's Association organizes activities to raise awareness and support each year for Alzheimer's Awareness Month in June. They also have an Alzheimer's Navigator service to develop personalized plans of action with support from local services.

How do you die from Alzheimer's?

Eventually, Alzheimer's disease progresses to the severe stage, where neurological damage causes the loss of the ability to walk, control bladder and bowels or feed independently. This is often the time when hospice care should be considered. Usually, the cause of death is from a secondary infection, such as pneumonia. Other conditions, such as a heart attack, dehydration, malnutrition, injuries from falls, pressure ulcers, stroke, kidney failure or lung infections from aspiration, contribute to organ failure and death.

In summary, Alzheimer's is a progressive, incurable disease with three stages. Early diagnosis and healthy lifestyle choices are critical measures to better management. Caregivers should seek resources and support to stay strong during the duration of the disease.

Updated September 2021.

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