The seven stages of Alzheimer’s disease span an average of 8 to 10 years from diagnosis to death, though the full trajectory from the earliest undetectable brain changes to the final stage can stretch across two decades or more. Based on the Global Deterioration Scale developed by Dr. Barry Reisberg at NYU Grossman School of Medicine, the stages break down roughly like this: the preclinical and very mild stages can persist for 15 years or longer, mild cognitive decline lasts about 7 years, mild dementia about 2 years, moderate dementia about 1.5 years, moderately severe dementia about 2.5 years, and severe dementia up to 2.5 years. A 72-year-old woman who starts forgetting appointments and losing her train of thought in conversation might not receive a formal diagnosis for another several years, and from that diagnosis, she could live anywhere from 4 to 8 years — or in some cases, up to 20.
These numbers matter because families need them for planning, but they also come with a critical caveat: no two people move through Alzheimer’s on the same schedule. Age at onset, sex, genetics, cardiovascular health, and access to care all bend the timeline. What the staging framework offers is not a countdown but a map — a way to understand where someone is and what kinds of support they are likely to need next. This article walks through each of the seven stages in detail, covering the symptoms that define them, how long each typically lasts, what caregivers should watch for, and how new disease-modifying treatments approved in 2023 and beyond are beginning to change the conversation about slowing progression.
Table of Contents
- What Are the 7 Stages of Alzheimer’s and How Long Does Each One Last?
- Why Alzheimer’s Timelines Vary So Widely Between Patients
- Who Is Most Affected — The Demographics Behind the Numbers
- What Caregivers Should Expect and Plan for at Each Stage
- New Treatments That May Change How Long Each Stage Lasts
- The Sub-Stages of Stage 6 — Why One Stage Spans So Much Loss
- Looking Ahead — What the Next Decade May Bring for Alzheimer’s Staging and Treatment
- Conclusion
- Frequently Asked Questions
What Are the 7 Stages of Alzheimer’s and How Long Does Each One Last?
The seven-stage model divides Alzheimer’s into a continuum that runs from completely normal cognition to profound disability. Stages 1 through 3 are considered pre-dementia — the person may notice changes, and a clinician might detect subtle deficits on testing, but the individual can still function independently. Stages 4 through 7 represent the dementia phases, where cognitive losses become impossible to ignore and progressively erode the ability to manage daily life. Stage 1, normal function with no symptoms, can last years to decades. Stage 2, where a person experiences subjective forgetfulness like misplacing keys or blanking on familiar names, can persist for up to 15 years. Most people in Stage 2 never suspect Alzheimer’s because these lapses look identical to ordinary aging. Stage 3 — mild cognitive decline, sometimes called mild cognitive impairment — is where the disease becomes clinically detectable. Memory problems grow noticeable to family and coworkers: the person gets lost driving to a familiar restaurant, struggles to find the right word in meetings, or can’t retain the content of something they just read. This stage lasts approximately 7 years in otherwise healthy individuals.
Once a person crosses into Stage 4, mild dementia, the average duration shortens to about 2 years, though some remain in this stage for up to 7. Here the person has difficulty managing finances, planning travel, or following complex conversations, but they typically still know who they are and recognize family members. The later stages compress further. Stage 5, moderate dementia, lasts roughly 1.5 years on average. The person can no longer live alone — they may forget their own address or phone number and need help selecting appropriate clothing. Stage 6, moderately severe dementia, averages about 2.5 years and is subdivided into five sub-stages (6a through 6e) tracking the sequential loss of the ability to dress, bathe, toilet independently, and maintain continence. Stage 7, the final stage, can also last up to 2.5 years. Speech deteriorates from a few words to none, and the person gradually loses the ability to walk, sit upright, and eventually smile. It is a brutal narrowing of the world, and understanding its contours helps families prepare rather than be blindsided.
Why Alzheimer’s Timelines Vary So Widely Between Patients
The durations listed above are averages, and averages can mislead. Average survival after an Alzheimer’s diagnosis is 4 to 8 years, but some people live 20 years post-diagnosis. The combined preclinical and prodromal stages alone last an estimated 17 years according to research published in PMC. This means that by the time a family hears the word “Alzheimer’s” from a neurologist, the disease has likely been silently remodeling the brain for well over a decade. Several factors push the timeline longer or shorter. Research has shown that younger age at onset, female sex, and lower levels of cerebrospinal fluid total tau protein are associated with a longer duration of the Alzheimer’s dementia stage. A person diagnosed at 62 may live with the disease far longer than someone diagnosed at 82, partly because their overall physical health tends to be more robust.
However, if a patient has significant cardiovascular disease, diabetes, or other comorbidities, the trajectory can accelerate regardless of age. The influence of the APOE genotype — the gene most strongly linked to late-onset Alzheimer’s risk — on disease duration remains equivocal. Carrying one or two copies of the APOE e4 allele clearly raises the probability of developing the disease, but the evidence on whether it speeds up progression once the disease takes hold is mixed. This variability is why staging should be treated as a framework, not a sentence. A family told their mother is in Stage 5 should not assume she has exactly 1.5 years left in that stage. She might stabilize for three years. She might decline faster if she develops pneumonia or a urinary tract infection that triggers delirium. The staging model is most useful when it informs planning — when to arrange power of attorney, when to consider in-home care, when residential placement becomes a realistic conversation — rather than when it becomes a source of false precision.
Who Is Most Affected — The Demographics Behind the Numbers
alzheimer‘s disease is not distributed equally across the population, and understanding who bears the greatest burden helps contextualize the staging framework. In 2025, 7.2 million Americans age 65 and older are living with Alzheimer’s — a historic milestone, the first time that number has exceeded 7 million. That translates to 1 in 9 people, or about 11 percent, of everyone in the United States over 65. The disease is overwhelmingly concentrated in older age groups: 74 percent of those with Alzheimer’s are 75 or older. But it is not exclusively a disease of old age — approximately 200,000 Americans under 65 have younger-onset dementia, and their experience of the stages can differ substantially from that of older patients. Sex plays a significant role. Almost two-thirds of Americans with Alzheimer’s are women.
Part of this gap is explained by longevity — women live longer, so more women reach the ages where Alzheimer’s prevalence is highest — but biological and hormonal factors may also contribute. For a 65-year-old woman, the remaining lifetime risk of developing Alzheimer’s is roughly double that of a 65-year-old man. This has practical implications: a woman diagnosed at 70 may face a longer total disease course, spending more years in the later stages, which translates into greater caregiving demands and higher costs. The financial weight of those demands is staggering. Health and long-term care costs for Alzheimer’s and other dementias are projected to reach $384 billion in 2025. Without medical breakthroughs that prevent, slow, or cure the disease, the number of Americans with Alzheimer’s is expected to hit 13.8 million by 2060, and annual costs could approach $1 trillion by 2050. These figures are not abstract — they represent families draining retirement savings, adult children leaving jobs to provide care, and a healthcare system straining under a burden it was not designed to carry.
What Caregivers Should Expect and Plan for at Each Stage
The early stages — 1 through 3 — are the planning window, and families who use it wisely spare themselves enormous stress later. During Stage 2 and early Stage 3, the person with Alzheimer’s is still capable of participating in legal and financial decisions. This is the time to establish a durable power of attorney, update wills, discuss preferences for future care, and designate a healthcare proxy. Waiting until Stage 4 or later risks a situation where the person can no longer meaningfully consent, which can trigger costly and emotionally draining guardianship proceedings. The tradeoff families face is between autonomy and safety. In Stage 4, a person with mild dementia may insist they can still drive, manage their own medications, and live alone. In many cases, they can — with oversight. But the margin for error narrows quickly.
A Stage 4 patient who mismanages a medication and ends up hospitalized, or who gets lost driving in an unfamiliar area, may need a level of intervention they resist. Families often describe this as the hardest phase emotionally, because the person looks and sounds mostly like themselves but is losing the capacity for reliable judgment. By contrast, Stage 6, while objectively more severe, often brings a strange simplification: the person clearly needs full-time care, decisions about independence are no longer ambiguous, and the caregiver’s role, while physically exhausting, is at least unambiguous. Stage 5 is the pivot point. The Alzheimer’s Association data indicates this is when independent living becomes unsafe. The person in Stage 5 may wander, leave the stove on, or be unable to manage hygiene without prompting. In-home care — whether from a family member, a hired aide, or both — becomes necessary. Memory care facilities become a realistic option to evaluate, and touring them before a crisis arises gives families time to make an informed choice rather than a desperate one.
New Treatments That May Change How Long Each Stage Lasts
For decades, Alzheimer’s treatment was limited to symptom management — drugs like donepezil and memantine that modestly improved cognition or behavior without touching the underlying disease. That changed in 2023 with the full FDA approval of lecanemab, marketed as Leqembi, the first disease-modifying therapy proven to slow the rate of cognitive decline. In clinical trials, lecanemab reduced the rate of decline by 27 percent over 18 months compared to placebo. It does not stop or reverse the disease, but a 27 percent slowing is meaningful: it may translate into additional months of preserved function, more time in the earlier stages, and delayed entry into the later ones. Lecanemab’s administration has also evolved rapidly. In January 2025, the FDA approved a once-every-four-weeks maintenance dosing schedule, reducing the initial burden of biweekly infusions. By August 2025, the FDA approved a once-weekly self-administered subcutaneous injection called Leqembi Iqlik, which allows patients to take the drug at home rather than in an infusion center.
A second drug, donanemab, marketed as Kisunla, also received FDA approval. Donanemab is a monthly infusion with a notable feature: treatment can be discontinued once brain scans show that amyloid plaque has been cleared, potentially limiting both cost and side-effect exposure. However, these therapies carry real risks that families must weigh carefully. Both lecanemab and donanemab can cause amyloid-related imaging abnormalities — brain swelling (ARIA-E) or small brain bleeds (ARIA-H). The risk is particularly elevated in carriers of the APOE e4 gene variant, and the FDA recommends genetic testing before initiating treatment. For a Stage 3 or early Stage 4 patient who is otherwise healthy and APOE e4-negative, the risk-benefit calculation may favor treatment. For an older patient in Stage 5 with significant vascular risk factors and two copies of e4, the calculus shifts. These drugs are not miracle cures, but they represent the first real evidence that the biological progression of Alzheimer’s can be slowed pharmacologically, and that distinction matters.
The Sub-Stages of Stage 6 — Why One Stage Spans So Much Loss
Stage 6 deserves special attention because it encompasses a broader range of decline than any other single stage. Dr. Reisberg’s framework breaks it into five sub-stages — 6a through 6e — that track a specific sequence of functional losses. In 6a, the person can no longer select appropriate clothing without assistance. In 6b, they lose the ability to bathe properly. Stage 6c brings the inability to manage toileting mechanics.
In 6d, urinary incontinence develops, and in 6e, fecal incontinence follows. The total duration of Stage 6 averages about 2.5 years, but the lived experience of a family moving through it is anything but uniform. A daughter caring for her father in Stage 6a may still be managing with part-time help and careful wardrobe simplification — elastic waistbands, shoes without laces, a limited selection in the closet. By 6d, the same family is dealing with round-the-clock incontinence care, skin integrity concerns, and the physical demands of transferring a confused adult who may resist assistance. The sub-stages are clinically useful because they allow care teams to anticipate needs before they become crises. A patient entering 6b should have a bathroom safety assessment. A patient entering 6d needs an incontinence management plan and possibly a reassessment of whether the current care setting can provide adequate support.
Looking Ahead — What the Next Decade May Bring for Alzheimer’s Staging and Treatment
The approval of lecanemab and donanemab has shifted the field from symptom management to disease modification, but the next generation of research aims higher. Trials are now exploring whether amyloid-clearing drugs can be effective in preclinical Alzheimer’s — Stages 1 and 2 — before symptoms appear, potentially delaying the onset of cognitive decline by years. Blood-based biomarker tests that can detect Alzheimer’s pathology decades before symptoms emerge are moving toward clinical availability, which could redefine what Stage 1 means in practice: not simply “no symptoms” but “no symptoms, confirmed negative for amyloid accumulation.” If treatments can reliably extend the earlier stages by even a few years, the implications for the projected 13.8 million cases by 2060 are enormous.
Keeping people in Stages 1 through 3 longer means fewer people in the high-cost, high-dependency later stages at any given time. It means fewer families making the wrenching decision to place a loved one in memory care. It does not mean Alzheimer’s is solved — the disease is still progressive, still incurable, still devastating — but the map is slowly being redrawn, and the stages that once felt like an inevitable downhill slide may become a landscape where intervention buys real, measurable time.
Conclusion
The seven stages of Alzheimer’s provide a necessary framework for understanding a disease that unfolds over years and sometimes decades. From the silent brain changes of Stage 1 through the profound losses of Stage 7, the timeline averages 8 to 10 years post-diagnosis but can extend to 20. The key durations to remember are Stage 3’s roughly 7-year window where early intervention is possible, the 2-year average of Stage 4 where diagnosis typically occurs, and the compressed but intensive final stages where full-time care becomes essential. With 7.2 million Americans now living with the disease and costs projected to approach $1 trillion annually by mid-century, the stakes of understanding these stages extend far beyond individual families. The most actionable takeaway is that the earlier stages are the planning stages.
Legal documents, financial arrangements, care preferences, and family conversations should happen while the person can still participate. Families who wait until a crisis in Stage 5 or 6 consistently report greater stress, worse outcomes, and higher costs than those who used the Stage 3 and 4 window to prepare. Meanwhile, the arrival of disease-modifying therapies like lecanemab and donanemab — imperfect as they are — offers the first genuine reason to pursue early diagnosis aggressively. Knowing the stage is no longer just about planning for decline. For some patients, it is becoming about accessing treatments that may slow the decline itself.
Frequently Asked Questions
Is the 7-stage model the only way to classify Alzheimer’s progression?
No. The 7-stage Global Deterioration Scale is the most detailed framework, but clinicians also use a simpler 3-stage model (early, middle, late) and the Clinical Dementia Rating scale. The GDS is most useful for caregiving planning because of its granularity, but your neurologist may use different terminology.
Can a person skip stages or go backward?
Alzheimer’s does not reverse, so true backward movement through the stages does not happen. However, a person may appear to improve temporarily due to better management of infections, medications, sleep, or nutrition. Stages can also seem to overlap, with a person showing characteristics of two adjacent stages simultaneously.
How long does a person typically live after being diagnosed with Alzheimer’s?
Average survival after diagnosis is 4 to 8 years, but this varies widely. Some people live up to 20 years after diagnosis, particularly those diagnosed at a younger age and with fewer comorbidities. The total disease course from earliest brain changes through death may span 17 years or more.
Are the new Alzheimer’s drugs available to everyone with the disease?
No. Lecanemab and donanemab are currently indicated for early-stage Alzheimer’s with confirmed amyloid pathology, typically Stages 3 and early 4. They are not approved for moderate or severe dementia. The FDA also recommends APOE genetic testing before starting treatment due to higher side-effect risks in e4 carriers.
Why are women disproportionately affected by Alzheimer’s?
Almost two-thirds of Americans with Alzheimer’s are women. Longevity is one factor — women live longer on average and thus spend more years in the highest-risk age brackets. But emerging research suggests hormonal changes at menopause, differences in brain connectivity, and other biological factors may also contribute to higher vulnerability.
At what stage should families consider memory care placement?
There is no single right answer, but Stage 5 is the most common inflection point. At this stage, the person can no longer live independently and may wander, forget to eat, or be unable to manage hygiene. Touring memory care facilities before reaching this stage allows families to make informed decisions rather than crisis-driven ones.
