How Alzheimer's Disease Progresses: From Diagnosis Through the 7 Stages

Alzheimer's disease is a progressive neurological condition that typically affects older adults and often causes memory loss, confusion, changes in behavior, and other troubling symptoms. It's the most common type of dementia. Approximately 10.7%—or one in nine—Americans over the age of 65 live with the condition, with women representing nearly two-thirds of cases.¹ As baby boomers continue to reach their golden years, the number of Americans with Alzheimer's disease is projected to rise to 7.16 million in 2025, and 13.9 million by 2060.²

To help physicians diagnose Alzheimer's disease, Dr. Barry Reisberg, a psychiatrist at the New York University School of Medicine developed the Global Deterioration Scale (GDS). The GDS defines seven distinct clinical stages of Alzheimer's disease.³ These seven stages are often condensed into a three-stage classification system: early stage, middle stage, and late stage. Stages one to three of the GDS are the early stages, stages four and five are middle stages, and stages six and seven are late stages.¹¹

Medical exams can help healthcare providers identify what stage someone may be in. Doctors typically use clinical interviews and medical evaluations when diagnosing Alzheimer's disease. The clinical interview typically includes questions such as how the person feels and what symptoms they might be experiencing, as well as exercises that test cognitive ability (e.g., "Can you count backward from 50?"). Depending on which stage someone with Alzheimer's disease is in, clinical interviews may be conducted alone or with a caregiver present at the doctor's appointment.⁸

Additionally, medical evaluations utilize brain imaging exams such as magnetic resonance imaging (MRI) or computed tomography (CT). The scans from these imaging tests can help doctors see evidence of tumors, strokes, build-up or fluid in the brain, or other damage caused by head trauma. Brain scans are typically used to rule out other neurological conditions such as a brain tumor or identify parts of the brain that may be shrinking. Shrinkage of your hippocampus, the brain component that is responsible for learning and memory, may indicate signs of memory loss.⁹

Stage 1: Preclinical Alzheimer's disease, No Sign of Dementia

In the first stage of the GDS, there are no issues with memory or thinking.³ All people begin at stage one, including those who will never develop the condition. The first three stages of Alzheimer's disease are called "preclinical stages". Clinical interviews and medical evaluations are not enough to detect Alzheimer's at this stage.

A different type of examination can potentially find biomarkers. A biomarker is a biological sign that measures the presence of a disease in your body. Blood pressure, heart rate, and x-rays are common examples of biomarkers.¹⁰ Some biomarkers may indicate low levels of beta-amyloid proteins and high levels of tau proteins, which were originally thought to serve as early warning signs of Alzheimer's disease.⁴

However, an investigation from July 2022 published in Science shed light on the fabrication of evidence about the importance of beta-amyloid proteins as a primary predictor of Alzheimer's disease.⁶ While scientists agree that beta-amyloid proteins are likely to be important in understanding Alzheimer's disease, further research may focus on other protein theories. For now, medical providers are likely to use a more holistic approach, such as behavioral or cognitive tests, for a proper diagnosis.⁷

Stage 2: Very Mild Cognitive Decline, Age-Related

Symptoms may start to become noticeable in the second stage of Alzheimer's disease. Similar to the first stage, this state does not show significant evidence of dementia in clinical interviews and evaluations. Some people may report growing memory problems, such as forgetting once familiar names or struggling to recall where they put their keys or wallet.³ In most cases, these issues are attributed to natural dips in cognitive function as you age.

Stage 3: Mild Cognitive Impairment

The third stage of Alzheimer's disease is also known as mild cognitive impairment (MCI). In this stage, you may begin to see clearer evidence of memory loss, lack of focus, and trouble thinking. According to the GDS, people experiencing two or more of the following symptoms are said to be at stage 3:³

• Getting lost when going to a location for the first time
• A decline in work performance that's noticeable to coworkers
• Forgetting names or "losing words"
• Retaining or remembering very little of what was just read, which can be determined through clinical evaluation
• Trouble remembering the names of newly-introduced people
• Losing a valued or treasured object, such as a wedding ring or social security card
• Worsening job performance
• Difficulty socializing with others
• Denial of memory problems or other cognitive issues
• Anxiety surrounding being unable to remember things

Unlike the previous stages, clinical tests and evaluations can pick up signs of impairment, especially issues related to concentration.³

Stage 4: Mild Dementia, Moderate Cognitive Decline

With stage 4 Alzheimer's disease, physicians are able to detect clear signs of Alzheimer's disease in clinical interviews and after careful evaluation. Those with this stage of Alzheimer's disease may experience difficulty remembering aspects of their personal life experiences and display reduced comprehension of current events. Other defining signs of this stage include:³

• Reduced understanding of current events or news
• Difficulty remembering aspects of personal history and life experiences
• Inability to repeatedly subtract by 7 starting from 100, which is found through a cognitive test
• Inability to travel independently, handle finances, or perform complicated tasks
• Denial of memory problems
• Lack of emotional expression (known as the flat affect)
• Frequent withdrawal from challenging or stressful social situations

People with stage 4 Alzheimer's disease are generally able to remember what time and day it is, where they are, and recognize familiar faces.

Stage 5: Moderate Dementia, Moderately Severe Decline

The fifth stage of Alzheimer's disease is known as moderate dementia. Clinical evaluation and interviews in these cases are able to root out memory and cognitive deficits. Those in this stage of Alzheimer's disease may have:³

• Trouble remembering important aspects of their life, such as their address, the names of close friends or family members, or the name of their hometown and schools
• Difficulty identifying the current date, day of the week, or season
• The inability to count down from 20 by twos or fours
• Difficulty getting dressed by themselves

Some people in this stage may retain long-term memories of major life events or the names of their spouse and children. Motor tasks such as using the restroom or eating independently may also come with ease.

Stage 6: Moderately Severe Dementia

A person in the sixth stage of Alzheimer's disease has noticeable difficulty with memory and thinking. General characteristics of stage 6 include:³

• Occasional inability to remember the names of a spouse, partner, or caregiver
• Difficulty or inability to recall recent life experiences or events
• Difficulty counting down from 10.
• Needing assistance for basic daily activities, such as bathing, using the bathroom, or getting dressed
• Disrupted sleep/wake cycles, insomnia, or other sleep problems

In addition, the sixth stage is marked by changes in personality and behavioral symptoms, such as:³

• Delusional behaviors, such as the belief that spouses or caregivers are imposters, or talking to imagined people or their image in the mirror
• Obsessive symptoms, such as compulsively cleaning the same area
• Feelings of anxiety, agitation, increased irritability, or violence
• Cognitive abulia, or a loss of desire or ability to carry out an action due to the inability to focus on a thought

Stage 6 substages

To help clinicians better identify the progression of this major stage of dementia, the stage can be further broken down into five substages, 6a to 6e. Here's a quick breakdown of some signs you may notice in a loved one with Alzheimer's disease within each substage.³

• Substage 6a: A person in this substage may have difficulty putting on clothes without help. They may forget how to tie their shoelaces or have a hard time distinguishing their left shoe from their right.
• Substage 6b: A person in this substage may struggle with bathing or washing on their own. This could include difficulty with filling a bath, finding a good water temperature, or using a towel to dry off. It is common for someone in this substage to feel fear or anxiety about bathing.
• Substage 6c: A person in this substage may lose the ability to use the toilet on their own. They may forget to flush, wipe, and pull up their underwear afterward.
• Substage 6d: A person in this substage may be unable to control their urination. This means that they may not know when they need to use the toilet or how to go to the bathroom. You may also notice your loved one urinating in their pants.
• Substage 6e: A person in the most advanced substage may have difficulty with fecal incontinence. This means that they may not know when they need to poop or how to use the toilet. People in this substage will need support when using the bathroom.

Stage 7: Very Severe Dementia

Stage 7 is the last stage of Alzheimer's disease. A person in this stage loses most if not all of their independence as thinking, memory, and control over bodily functions all severely decline. Common characteristics of stage 7 include:³

• Gradual loss of basic motor skills, such as the ability to walk or control their limbs
• Needing assistance with eating, bathing, and using the bathroom
• Losing the ability to speak or becoming nonverbal

Those in stage 7 will often require full-time support from a caregiver.

Stage 7 substages

There are six substages within stage 7. Understanding these substages can help providers and caregivers track disease progression of very serious dementia.³

• Substage 7a: A person in this substage has difficulty speaking in full sentences. Eventually, they may only be able to say about six words at a time and become hesitant to speak.

• Substage 7b: A person in this substage has increased trouble with words. You may notice that they can only say "yes" or "OK." Over time, even this word can go away and may be replaced by vocalizations or soft grunts.

• Substage 7c: A person in this substage may gradually lose the ability to walk. They may start taking shorter steps, be unable to climb stairs, or tilt forward or side-ways when standing. Over time, they may not be able to move on their own without assistance.

• Substage 7d: A person in this substage may have difficulty sitting upright without help. They are typically still able to smile, chew, grunt, scream, and grasp items with their hands.

• Substage 7e: A person in this substage slowly loses the ability to smile or make facial expressions. They are still able to move their eyes but may struggle with recognizing familiar faces. However, they are still usually able to grasp items, chew and swallow food, and vocalize utterances.

• Substage 7f: A person in this final substage usually loses the ability to hold up their head. They may begin to require feeding tubes to eat and lose the ability to recognize food. While largely unresponsive, people in substage 7f may still make soft grunts or vocalizations. Typically, only a small number of people with Alzheimer's disease survive to this point.

Once someone has advanced through the stage 7 substages, the condition is dangerous and fatal, especially alongside other health issues. People between the ages of 75 and 85 with severe dementia (such as stage 7 Alzheimer's disease) often die within six months to two years of reaching stage seven, with women living longer than men.⁵ Notably, a majority of people with Alzheimer's disease do not make it to the later subtypes of stage 7.

Summary

Since 1982, the Global Deterioration Scale has helped physicians and caregivers better identify the progression of Alzheimer's disease through the seven stages.³ Living with Alzheimer's disease is difficult for those diagnosed with the condition as well as their loved ones. If you notice your loved one starting to display signs of Alzheimer's disease, do your best to help your loved one receive a proper diagnosis. While there is no cure for Alzheimer's disease at this time, medical intervention and therapies may help manage the condition or slow its progression. As a caregiver, you may also be interested in looking for programs that provide financial assistance for you and your loved one, or reach out to a mental health professional to manage the emotional toll caregiving may have on you. It is OK to ask for help as you navigate this difficult time.

Sources

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7. Lowe D. Faked beta-amyloid data. What does it mean? Science. Published July 25, 2022.

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