Understanding the Five Stages of Alzheimer’s Disease

Posted on by Emily Kil

You almost certainly have heard of Alzheimer’s disease. Alzheimer’s has been one of the most widely discussed medical conditions over the course of the past 25 years. With that said, you may be like many women and men from all walks of life and not have a particular clear understanding of Alzheimer’s and its consequences. As a means of enabling you to better understand Alzheimer’s, we provide you with this discussion of the five stages of the disease:

  • Preclinical Alzheimer’s disease
  • Mild cognitive impairment due to Alzheimer’s disease
  • Mild dementia due to Alzheimer’s disease
  • Moderate dementia due to Alzheimer’s disease
  • Severe dementia due to Alzheimer’s disease

In order to better understand the five stages of Alzheimer’s disease, we first present you with a prelude in which we provide you more information about:

  • Alzheimer’s disease
  • Cognitive impairment
  • Dementia

You need to have a clearer understanding of these conditions in order to really grasp what is and is not occurring in each of the stages of Alzheimer’s disease.

What Is Alzheimer’s Disease?

As we mentioned a moment ago, if you are like most people, you certainly have heard of Alzheimer’s disease and understand somethings about it. However, if you are also like many individuals, you really can stand to have more information about the disease to better understand Alzheimer’s.

Clinically speaking, Alzheimer’s is defined as:

A brain disorder that slowly destroys memory and thinking skills and, eventually, the ability to carry out the simplest tasks. In most people with the disease — those with the late-onset type symptoms first appear in their mid-60s. Early-onset Alzheimer’s occurs between a person’s 30s and mid-60s and is very rare. Alzheimer’s disease is the most common cause of dementia among older adults. (National Institute on Aging)

Alzheimer’s is named after Dr. Alois Alzheimer. It was Dr. Alzheimer who noticed changes in the brain tissue of a woman who had died of an unusual mental illness. This happened in 1906. The woman’s symptoms included:

  • Memory loss
  • Language problems
  • Unpredictable behavior

When the woman died, Dr. Alzheimer examined her brain and found many abnormal clumps (which are now called amyloid plaques) and tangled bundles of fibers (which are now called neurofibrillary, or tau, tangles).

These plaques and tangles in the brain are still considered some of the primary features of Alzheimer’s disease. Another feature of Alzheimer’s disease is the loss of connections between nerve cells (biologically known as neurons) in the brain. Neurons transmit messages between different parts of the brain, and from the brain to muscles and organs in the body. Many other complex brain changes are thought to play a role in Alzheimer’s as well. 

This damage to a person’s brain initially happens in parts of the brain involved in memory. These include the entorhinal cortex and hippocampus. Overtime, Alzheimer’s affects areas in the cerebral cortex. The diseases also effects areas in the brain responsible for:

  • Language
  • Reasoning
  • Social behavior

Ultimately, many other areas of the brain are damaged as the result of the progression of Alzheimer’s disease.

What Is Cognitive Impairment?

Cognitive impairment is not an illness or disease. Cognitive impairment is a description of a person’s condition. 

Cognitive impairment means that an individual has issues with things like memory or paying attention. A person with cognitive impairment might have trouble speaking or understanding. In some instances, an individual with cognitive impairment might have difficulty recognizing people, places, or things that should be familiar. A person with cognitive impairment may find new places, people, or situations overwhelming.

What Is Dementia?

The U.S. Centers for Disease Control and Prevention provides us with a succinct definition of dementia:

Dementia is not a specific disease but is rather a general term for the impaired ability to remember, think, or make decisions that interferes with doing everyday activities. Alzheimer’s disease is the most common type of dementia. Though dementia mostly affects older adults, it is not a part of normal aging.

Examples of memory lapses that are a normal part of aging include:

  • Occasionally misplacing car keys
  • Struggling to find a word but remembering it later
  • Forgetting the name of an acquaintance
  • Forgetting the most recent events

Even walking into a room and not remembering why you did so is a memory lapse that is typical of the normal aging process.

On the other hand, signs or symptoms that an individual may have dementia include:

  • Getting lost in a familiar neighborhood
  • Using unusual words to refer to familiar objects
  • Forgetting the name of a close family member or friend
  • Forgetting old memories
  • Not being able to complete tasks independently

Alzheimer’s disease is a form of dementia. In fact, Alzheimer’s is the most common type of dementia affecting older Americans in this day and age. 

With this general information in mind, we now turn to the five stages of Alzheimer’s disease.

Preclinical Alzheimer’s Disease

Ultimately, the effects of Alzheimer’s disease are extremely apparent. At the other extreme, a person can be in the preclinical stage of Alzheimer’s disease for years or even decades and have no idea this is the case. People around a person in the first stage or preclinical stage of Alzheimer’s would have no idea the individual is harboring the beginnings of the disease in his or her brain. 

There are now technologies available that can identify deposits of a particular protein in a person’s brain that are considered a hallmark of Alzheimer’s disease. This protein is called amyloid-beta. While there is no cure for Alzheimer’s disease at this time, the ability to identify this protein in the brain is vital for research and ultimately for finding a cure to this dreaded disease. 

In addition, certain biomarkers have been identified for Alzheimer’s disease. Biomarkers are measures that can indicate an increased risk or likelihood of a particular disease, including Alzheimer’s. When it comes to biomarkers, these tend to be most useful when an individual is exhibiting early cognitive symptoms that might be indicative of the onset of Alzheimer’s.

Finally, genetic testing can also ascertain if a person is at a higher risk of Alzheimer’s disease. Genetic testing has proven particularly useful in identifying individuals that are at higher risk for early onset Alzheimer’s. 

Mild Cognitive Impairment Due to Alzheimer’s Disease

The second stage of Alzheimer’s disease progression is mild cognitive impairment. Individuals with Alzheimer’s associated mild cognitive impairment have minimal (mild) changes in thinking and memory. These changes are not significant enough to impact work, relationships, or basic activities of daily living.

With that said, mild cognitive impairment consists of memory lapses that are slightly outside of the range of what is expected in the normal aging process. Examples of these types of memory lapses can include:

  • Forgetting otherwise easily remembered conversations
  • Forgetting recent events with some degree of frequency
  • Forgetting appointments, again with some degree of frequency

In addition, people with mild cognitive impairment that might be indicative of Alzheimer’s disease also:

  • Have difficulty judging the amount of time needed for a task
  • Difficulty judging the number of steps needed to complete a task
  • Difficulty judging the sequence of steps to be taken to complete a task

Finally, people with mild cognitive impairment that might be an indicator of Alzheimer’s disease may find it harder to make sound decisions.

Having said all of this, it is important to remember that not all individuals with mild cognitive impairment have Alzheimer’s disease. 

Mild Dementia Due to Alzheimer’s Disease

The third stage of Alzheimer’s typically is when a formal diagnosis is made of the disease. The third stage of disease is that of mild dementia due to Alzheimer’s. It is at this stage that people around a person with mild dementia become clearly aware that the individual is having significant issues with thinking and memory. These issues of thinking and memory are impacting an individual’s daily functioning. 

Examples of what a person in the third stage of Alzheimer’s disease may experience include:

  • Memory loss of recent events and information: Individuals may have a particularly difficult time remembering newly learned information and recalling recent events. An individual may ask the same question over and over again.
  • Difficulty with problem-solving, complex tasks, and sound judgments: Planning a family event or balancing a checkbook may become overwhelming. Many people experience lapses in judgment, such as when making financial decisions.
  • Changes in personality: People may become subdued or withdrawn. This will especially be the case in socially challenging situations. Individuals at this stage of the disease may also begin to demonstrate previously uncharacteristic irritability or anger. Reduced motivation to complete tasks also is common at this stage of Alzheimer’s disease.
  • Difficulty organizing and expressing thoughts: Finding the right words to describe objects or clearly express ideas becomes increasingly challenging.
  • Getting lost or misplacing belongings: Individuals have increasing trouble finding their way around, even in familiar places. It’s also common to lose or misplace things, including valuable items.

Moderate Dementia Due to Alzheimer’s Disease

The fourth stage of Alzheimer’s disease is identified by moderate dementia. People in the fourth stage of Alzheimer’s are:

  • More confused
  • More forgetful
  • Begin to require assistance with activities of daily living
  • Begin needing assistance with self-care (bathing, groom, dressing, and so forth)

People in the fourth stage of Alzheimer’s afflicted with moderate dementia may also:

  • Show increasingly poor judgment and demonstrate deepening confusion. Individuals lose track of where they are at any given moment. They also lose track of the day of the week or the season of the year. They may begin to confuse family members or close friends with one another. They may also mistake strangers for family.
  • They may begin to wander. Some experts hypothesize that they wander because they are possibly in search of surroundings that feel more familiar. These difficulties make it unsafe to leave those in the moderate dementia stage on their own. While it may still be possible to age at home in this stage, the need for a 24-hour caretaker becomes necessary. In a majority of cases, this ends up being a family member (usually a spouse or a child of the person in this stage of Alzheimer’s). 
  • Experience even greater memory loss. People may forget details of their personal history, such as their address or phone number, or where they attended school. They repeat favorite stories or make up stories to fill gaps in memory.
  • Some individuals occasionally lose control of their bladder or bowel movements.
  • Undergo significant changes in personality and behavior. 
  • It’s not unusual during the moderate dementia stage for people to develop unfounded suspicions (for example, to become convinced that friends, family or professional caregivers are stealing from them or that a spouse is having an affair). Others may see or hear things that aren’t really there.
  • Individuals often grow restless or agitated, especially late in the day. 
  • Some people may have outbursts or aggressive physical behavior.

Severe Dementia Due to Alzheimer’s Disease

In the fifth and final stage of Alzheimer’s, the symptoms are profound, even shocking. At this stage, the disease has an ever-increasing impact on functioning beyond that associated with cognitive abilities and memory. Alzheimer’s has a growing impact on a person’s movement, mobility, and other physical abilities. 

In the fifth stage of Alzheimer’s disease, people usually will:

  • Lose the ability to communicate in a coherent manner: An individual can no longer converse or speak in ways that make sense. A person may occasionally say words or phrases, however.
  • Require daily assistance with personal care: This includes total assistance with eating, dressing, using the bathroom, and all other daily self-care tasks.
  • Experience a decline in physical abilities: A person may become unable to walk without assistance. In time, an individual may become unable to sit or hold up his or her head without support. Muscles may become rigid, reflexes abnormal. Ultimately, a person in the final stage of Alzheimer’s disease loses the ability to swallow and to control bladder and bowel functions.

In closing, after presenting this foundational information about Alzheimer’s disease, we share a quote to reflect upon if you or someone in your own life may be somewhere amongst the stages discussed in this article:

Alzheimer’s is not about the past – the successes, the accolades, the accomplishments. They offer only context and are worthless on places like Pluto. Alzheimer’s is about the present and the struggle, the scrappy brawl, the fight to live with a disease. It’s being in the present, the relationships, the experiences, which is the core of life, the courage to live in the soul.
― Greg O’Brien, On Pluto: Inside the Mind of Alzheimer’s