Alzheimer’s Disease: Signs, Symptoms, and Stages

Alzheimer’s disease is one of the scariest prospects many of us face as we age. Here’s how to recognize the symptoms and differentiate them from normal signs of aging.

Concerned daughter comforts elderly mother who looks out blankly towards window

What is Alzheimer’s disease?

Alzheimer’s disease is the most common form of dementia, a brain disorder that impacts daily living through memory loss and cognitive changes. Although not all memory loss indicates Alzheimer’s, the Alzheimer’s Association reports that one in ten people over 65 years of age, and nearly one-third of those over 85, have Alzheimer’s.

Symptoms of Alzheimer’s usually develop slowly and gradually worsen over time, progressing from mild forgetfulness to widespread brain impairment. As critical cells die, drastic personality loss occurs and body systems fail.

Suspecting you or a loved one may be exhibiting signs of Alzheimer’s can be a frightening and stressful experience. Even when your worst fears are realized, the earlier you’re diagnosed and seek help, the better your chances of delaying the onset of more debilitating symptoms, prolonging your independence, and maximizing your quality of life.

Alzheimer’s disease risk factors

While the primary risk factors of Alzheimer’s are age, family history, and genetics, there are other risk factors that you can influence. Maintaining a healthy heart and avoiding high blood pressure, heart disease, stroke, diabetes, and high cholesterol can significantly decrease your risk. Watching your weight, avoiding tobacco and excess alcohol, staying socially connected, and exercising both your body and mind can also help protect against the disease.

Early-onset Alzheimer’s affects patients under the age of 65. This relatively rare condition is seen more often in patients whose parents or grandparents developed Alzheimer’s disease at a young age.

Signs and symptoms of Alzheimer’s disease

For many people, detecting the first signs of memory problems in themselves or a loved one brings an immediate fear of Alzheimer’s disease. However, most of us over 65 experience some level of forgetfulness. It is normal for age-related brain shrinkage to produce changes in processing speed, attention, and short-term memory, creating so-called “senior moments.” Understanding the significance of these age-related changes begins with knowing the difference between what is normal and what is an early symptom of Alzheimer’s.

Signs of Normal Change vs. Early Alzheimer’s Symptoms
Normal change: Can’t find your keys

Early Alzheimer’s: Routinely place important items in odd places, such as keys in the fridge, wallet in the dishwasher

Normal change: Search for casual names and words

Early Alzheimer’s: Forget names of family members and common objects, or substitute words with inappropriate ones

Normal change: Briefly forget conversation details

Early Alzheimer’s: Frequently forget entire conversations

Normal change: Feel the cold more

Early Alzheimer’s: Dress regardless of the weather. For example, wearing several skirts on a warm day, or shorts in a snow storm

Normal change: Can’t find a recipe

Early Alzheimer’s: Can’t follow recipe directions

Normal change: Forget to record a check

Early Alzheimer’s: Can no longer manage checkbook, balance figures, solve problems, or think abstractly

Normal change: Cancel a date with friends

Early Alzheimer’s: Withdraw from usual interests and activities, sit in front of the TV for hours, sleep far more than usual

Normal change: Make an occasional wrong turn

Early Alzheimer’s: Get lost in familiar places, don’t remember how you got there or how to get home

Normal change: Feel occasionally sad

Early Alzheimer’s: Experience rapid mood swings, from tears to rage, for no discernible reason

What else can cause Alzheimer’s symptoms?

While significant cognitive and memory loss are NOT symptoms of normal aging, these symptoms do not always indicate Alzheimer’s disease. Other conditions can mimic early Alzheimer’s symptoms, such as:

Central nervous system and other degenerative disorders, including head injuries, brain tumors, stroke, epilepsy, Pick’s Disease, Parkinson’s disease, Huntington’s disease.

Metabolic ailments, such as hypothyroidism, hypoglycemia, malnutrition, vitamin deficiencies, dehydration, kidney or liver failure.

Substance-induced conditions, such as drug interactions, medication side-effects, alcohol and drug abuse.

Psychological factors, such as dementia syndrome, depression, emotional trauma, chronic stress, psychosis, chronic sleep deprivation, delirium.

Infections, such as meningitis, encephalitis, and syphilis.

Alzheimer’s disease vs. mild cognitive impairment (MCI)

Early dementia, also known as mild cognitive impairment (MCI), involves problems with memory, language, or other cognitive functions. But unlike those with full-blown Alzheimer’s, people with MCI are still able to function in their daily lives without relying on others.

According to the Alzheimer’s Association, about 15 to 20 percent of people over the age of 65 experience mild cognitive impairment. Many people with MCI eventually develop Alzheimer’s disease or another type of dementia. However, others plateau at a relatively mild stage of decline and are able to live independently. Some people with mild cognitive impairment even return to normal.

Symptoms of MCI include:

  • Frequently losing or misplacing things
  • Frequently forgetting conversations, appointments, or events
  • Difficulty remembering the names of new acquaintances
  • Difficulty following the flow of a conversation

It is not yet fully understood why MCI progresses to Alzheimer’s disease in some, while remaining stable in others. The course is difficult to predict, but in general, the greater the degree of memory impairment, the greater the risk of developing Alzheimer’s down the line.

Diagnosing Alzheimer’s disease

There is no single definitive medical test for identifying Alzheimer’s. To make a diagnosis from your symptoms, a doctor will look for:

Significant memory problems in immediate recall, short-term, or long-term memory.

Significant thinking deficits in at least one of four areas:

  1. expressing or comprehending language
  2. identifying familiar objects through the senses
  3. coordination, gait, or muscle function
  4. the executive functions of planning, ordering, and making judgments

Decline severe enough to interfere with relationships and/or work performance.

Symptoms that appear gradually and become steadily worse over time.

Other causes to be ruled out to ensure memory and cognitive symptoms are not the result of another medical condition or disease, such as mild cognitive impairment.

Coping with a diagnosis

An Alzheimer’s diagnosis can be a life-altering experience for both you and your loved ones. But it doesn’t mean that your life is over. While there is currently no cure, there are treatments available for the symptoms. Lifestyle changes may also help slow the progression of the disease and delay the onset of more debilitating symptoms. Receiving an early diagnosis can prolong your independence and help you to live life fully for much longer.

Slowing the progression of symptoms

The same healthy lifestyle changes that are used to prevent Alzheimer’s disease can also be useful in slowing the advancement of symptoms.

  1. Get regular exercise to stimulate your brain’s ability to maintain old connections, make new ones, and slow deterioration of cognitive abilities.
  2. Social engagement, connecting face-to-face with others, can help improve your cognitive function.
  3. Eating a brain-healthy diet can help reduce inflammation and promote better communication between brain cells.
  4. Mental stimulation, learning new things, and challenging your brain can help strengthen your cognitive skills.
  5. Getting quality sleep can flush out brain toxins and avoid the build-up of damaging plaques.
  6. Managing stress can help slow shrinking to a key memory area of the brain and protect nerve cell growth.
  7. Taking care of your heart, controlling your blood pressure and cholesterol levels, can be just as good for your brain health.

To learn more about putting these strategies into action, see Preventing Alzheimer’s Disease.

Stages of Alzheimer’s disease: 3-stage model

Understanding the different stages of Alzheimer’s can help you to track the progression of symptoms and plan appropriate care. However, it is important to remember that everyone with Alzheimer’s disease progresses differently and there are steps you can take to slow the onset of symptoms at each stage. Cognitive, physical, and functional phases often overlap, the time in each stage varies from patient to patient, and not everyone experiences all symptoms.

In the three-stage Alzheimer’s disease model:

Stage 1 – Mild/Early 

Many people at this stage experience frequent recent memory loss, particularly of recent conversations and events. They may ask repeated questions and have some problems expressing and understanding language. Mild coordination problems include having difficulty writing and using objects. Depression and apathy can occur, accompanied by mood swings. They may need reminders for daily activities and have difficulty driving.

Duration: 2 to 4 years.

Stage 2 – Moderate/Middle 

People at this stage can likely no longer cover up problems. Pervasive and persistent memory loss includes forgetfulness about their personal history and inability to recognize friends and family. They may experience rambling speech, unusual reasoning, and confusion about current events, time, and place. They’re more likely to become lost in familiar settings, experience sleep disturbances, and changes in mood and behavior, which can be aggravated by stress and change. Experiencing delusions, aggression, and uninhibited behavior are common. Mobility and coordination is affected by slowness, rigidity, and tremors. They need structure, reminders, and assistance with the activities of daily living.

Duration: 2 to 10 years.

Stage 3 – Severe/Late 

In late stage Alzheimer’s, most people are confused about past and present. They lose the ability to remember, communicate, or process information. They’re generally incapacitated with severe to total loss of verbal skills, unable to care for themselves, and likely immobile and prone to falls. Problems with swallowing, incontinence, and illness are also common. Many also experience extreme problems with mood, behavior, hallucinations, and delirium. They need around the clock care.

Duration: 1 to 3+ years.

Stages of Alzheimer’s disease: 7-stage model

In addition to the three stages of Alzheimer’s, your doctor may also use a diagnostic framework with five, six, or seven levels. Progression through these stages usually lasts from 8 to 10 years, but again, differs from person to person and can stretch out for as long as 20 years.

Sample seven stage model of Alzheimer’s disease:

Stage 1 – No Impairment

Memory and cognitive abilities appear normal.

Stage 2 – Minimal Impairment/Normal Forgetfulness

Memory lapses and changes in thinking are rarely detected by friends, family, or medical personnel.

Stage 3 – Early Confusional/Mild Cognitive Impairment

While subtle difficulties begin to impact function, the person may try to cover up problems. They may have difficulty with retrieving words, planning, organization, misplacing objects, and forgetting recent learning, which can affect life at home and work. Depression and other changes in mood can also occur.

Duration: 2 to 7 years.

Stage 4 – Late Confusional/Mild Alzheimer’s disease

Mathematical challenges can cause problems handling finances. Increasingly, the person will forget recent events and conversations, although most people in this stage still know themselves and their family. Problems carrying out sequential tasks, including cooking, driving, ordering food at restaurants, and shopping are common. The person often withdraws from social situations, become defensive, and denying problems. Accurate diagnosis of Alzheimer’s disease is possible at this stage.

Duration: roughly 2 years.

Stage 5 – Early Dementia/Moderate Alzheimer’s disease

Decline is more severe and the person requires assistance. They’re no longer able to manage independently or recall personal history details and contact information. They’re frequently disoriented regarding place or time. People in this stage experience a severe decline in numerical abilities and judgement skills, which can leave them vulnerable to scams and safety problems. Basic daily living tasks like eating and dressing require increased supervision.

Duration: average of 1.5 years.

Stage 6 – Middle Dementia/Moderately Severe Alzheimer’s disease

People in this stage experience no longer aware of present events and unable to accurately remember the past. They progressively lose the ability to take care of daily living activities like dressing, toileting, and eating, but are still able to respond to nonverbal stimuli, and communicate pleasure and pain via behavior. Agitation and hallucinations often show up in the late afternoon or evening. Dramatic personality changes such as wandering or suspicion of family members are common. Many can’t remember close family members, but know they are familiar.

Duration: approximately 2.5 years.

Stage 7 – Late or Severe Dementia and Failure to Thrive

In this final stage, speech becomes severely limited, as well as the ability to walk or sit. Total support around the clock is needed for all functions of daily living and care.

Duration: impacted by quality of care, but average length is 1 to 2.5 years.

Get more help

New Approaches to Alzheimer’s Diseases (VIDEO) – Neurologist Verna Porter, MD, discusses new approaches to diagnosing and treating Alzheimer’s disease. (UCLA Health)

10 Ways to Love Your Brain – Tips for reducing your risk of cognitive decline. (Alzheimer’s Association)

Alzheimer’s Disease and Related Dementias – Series of articles covering different aspects of dementia including signs, symptoms, and caregiving. (National Institute on Aging)

Find support

In the U.S.: Call the Alzheimer’s Association helpline at 1 800 272 3900 or the Alzheimer’s Foundation of America at 1-866-232-8484.

UK: Call the Alzheimer’s Society helpline at 0300 222 1122 or find support near you.

Australia: Call the Dementia Australia helpline at 1800 100 500 or find support in your region.

Canada: Find an Alzheimer Society in your area.

India: Call the Alzheimer’s and Related Disorders Society of India 24-hour helpline in your area.

In other countries: Browse a worldwide directory of Alzheimer associations for information, advice, and support near you. (Alzheimer’s Disease International)

Authors: Lawrence Robinson and Jeanne Segal, Ph.D. Last updated: February 2020.