Alzheimer’s Disease

This article provides a comprehensive overview of Alzheimer’s disease, including the main features and symptoms, causes, how it affects the brain, and information regarding treatment and management options.

Key Takeaways:

• Alzheimer’s disease is the most common cause of dementia. It affects 1 in 10 individuals over 65 and 1 in 3 individuals over 85.
• Alzheimer’s is characterized by several key symptoms, such as problems with memory and thinking, altered behavior and personality, and poor judgment. Due to its progressive nature, these often get worse over time.
• There is no cure for Alzheimer’s, but certain medications and lifestyle components may help to slow disease progression. Ultimately, treatments and therapies are tailored to each individual to promote well-being and life quality as much as possible.

Understanding Alzheimer’s Disease

Alzheimer’s disease is a neurodegenerative condition characterized by the progressive loss of nerve cells and brain function over time. It is the most common cause of dementia (which is now typically referred to as major neurocognitive disorder).

Due to the deteriorating effects it has in the brain and nervous system, Alzheimer’s leads to disruptions in memory, learning ability, and overall cognitive function. It also contributes to behavioral and emotional disturbances too, such as personality changes and apathy. ^{[1] [2]}

Alzheimer’s starts to develop many years before symptoms show. Eventually, symptoms become great enough to significantly interfere with daily living and overall functioning. ^[3]

How Many People Have Alzheimer’s Disease?

Alzheimer’s disease affects roughly 24 million people worldwide. It accounts for 60 to 80% of all cases of dementia, and affects 1 in 10 individuals over 65, and 1 in 3 individuals over 85. Roughly two-thirds of Alzheimer’s cases are women. ^{[2] [3] [4]}

Is Alzheimer’s Disease the Same as Dementia?

Alzheimer’s disease is not the same as dementia. Rather, it is a specific cause (or type) of dementia with specific and distinct features.

Thus, dementia is a broader category with many other types, such as vascular dementia and frontotemporal dementia. Overall, there are many other possible causes of dementia.

Alzheimer’s Disease Symptoms

Alzheimer’s disease often affects memory, learning, reasoning, behavior, and personality. Listed below are the main symptoms of Alzheimer’s disease grouped by category.

Memory

One of the most common symptoms of Alzheimer’s disease is memory problems, which worsen over time. Specific memory symptoms include: ^{[2] [4] [5]}

• Repeating oneself (such as questions or statements)
• Forgetting conversations, appointments, and other events
• Misplacing items or putting them in the wrong spot
• Getting lost in familiar places
• Forgetting names of people, objects, places, etc.
• Inability to recognize familiar people

Thinking & Reasoning

Thinking and reasoning are also key cognitive functions commonly affected by Alzheimer’s. Specific symptoms include: ^{[2] [5]}

• Trouble concentrating
• Difficulty completing tasks
• Inability to multitask (or significant difficulty doing so)
• Difficulty with abstract concepts, such as numbers

Judgments and Decision-Making

Alzheimer’s can also affect key brain functions involved in judgments and decision-making processes. This may result in: ^{[2] [5]}

• Wearing the wrong clothes with respect to the weather
• Difficulty solving everyday problems
• Poor/incorrect choices within social settings

Planning and Performing Familiar Tasks

Individuals with Alzheimer’s also have difficulty planning and performing familiar tasks, such as: ^{[1] [2] [5]}

• Following a recipe/making a meal
• Playing a favorite game
• Getting dressed
• Personal hygiene routines

Language

Alzheimer’s disease may also affect language ability. Individuals may: ^{[1] [2]}

• Communicate or talk less than normal
• Say or use the wrong words
• Have trouble finding the right words to say

Personality and Behavior

Alzheimer’s also often leads to personality and behavior changes, which typically get more severe and/or more unusual over time. Specific symptoms include: ^{[1] [2] [3] [4] [5]}

• Acting suspiciously, even around familiar people
• Mood swings
• Anger or irritability
• Aggression
• Withdrawing from others
• Loss of interest in activities
• Paranoia, delusions, or hallucinations
• Lack of trust in oneself or others
• Wandering
• Restlessness
• Changes in sleeping habits
• Loss of inhibitions (may lead to inappropriate behaviors)

At What Age Does Alzheimer’s Present Itself?

Alzheimer’s disease often starts to present in older age. It affects 1 in 10 individuals over age 65 and 1 in 3 individuals over age 85. ^{[1] [2]}

However, Alzheimer’s can present in younger individuals too. Early-onset Alzheimer’s disease (which is in individuals younger than 65\) accounts for around 5% of all cases. For these individuals, symptoms typically start in their 40s and 50s.

Early Signs of Alzheimer’s Disease

There are several early signs that may indicate the development of Alzheimer’s disease, such as: ^{[1] [3] [4] [5]}

• Forgetting recent events or conversations
• Difficulty remembering newly learned information
• Slight to moderate changes in mood

These symptoms are mild overall, and not significant enough to prevent someone from performing everyday activities.

Causes

A key feature of Alzheimer’s disease is the build-up of specific proteins in the brain, which negatively affects nerve cell communication and eventually nerve cell death. What causes this to happen may vary from person to person, but it is likely a combination of genetic, lifestyle, and environmental factors. ^{[1] [2] [5]}

Examples of possible contributing causes include: ^{[1] [2] [5]}

• Hereditary/genetic factors, such as having the APOE e4 gene
• Traumatic brain injury
• Heavy alcohol use
• Air pollution
• Sleep issues
• Lack of exercise
• Smoking or secondhand smoke exposure
• Type 2 diabetes
• Obesity
• Immune system abnormalities

How Alzheimer’s Affects the Brain

One of the key defining physical features of Alzheimer’s disease is the presence of plaques and tangles. Specifically, this includes: ^{[1] [2] [4] [5]}

• Plaque build-up from amyloid protein, which takes up space in between nerve cells
• Tangles, which are formed from twisted fibers of tau proteins. These build up inside the nerve cells

Together, plaques and tangles block nerve cells’ ability to send signals and communicate with each other. Over time, this deteriorates their function and causes nerve cell death. ^{[4] [5] [6]}

Most often, this damage starts in areas of the brain linked to memory, including the hippocampus. Over time, the damage spreads to other areas and causes the brain to shrink in size. ^{[2] [5] [6]}

Alzheimer’s also leads to a reduced production of neurotransmitters, which are important for many brain functions. The most common one affected is acetylcholine, although serotonin and norepinephrine may also be affected. ^[1]

Other brain factors associated with Alzheimer’s are inflammation, blood vessel damage, free radical production, and mitochondrial dysfunction. ^{[1] [6]}

Who is at Most Risk of Developing Alzheimer’s?

Several factors increase your risk of developing Alzheimer’s. The people most at risk are those who: ^{[1] [2] [5] [6]}

• Are over age 65 (this is the strongest risk factor)
• Have a family history of Alzheimer’s disease
• Have the APOE e4 gene
• Have mild cognitive impairment

A generally unhealthy lifestyle (e.g. smoking, lack of exercise, overeating) also increases the risk. Certain medical conditions also pose a greater risk, such as heart disease, down syndrome, diabetes, and obesity. ^[1]

Diagnosing Alzheimer’s Disease

Diagnosing Alzheimer’s disease is done by a qualified health professional. There is no single test to diagnose Alzheimer’s disease, but a comprehensive evaluation and examination can provide a highly accurate diagnosis.

The first step is an initial consultation and evaluation by your doctor. They will ask you about your family, medical, and health history, and any symptoms you’ve noticed.

Very often, family or others closely involved will be asked these questions as well to gain a more complete picture. These individuals can often identify behavior changes that you may not notice from your own perspective.

Tests and Assessments

Numerous tests and assessments may be implemented when diagnosing Alzheimer’s disease. Firstly, this includes a comprehensive physical and neurological exam. Your doctor may implement a variety of tests to help identify possible causes and/or rule out other factors for your symptoms. Examples of these tests include

• Complete blood count
• Complete metabolic panel
• Thyroid-stimulating hormone
• Vitamin B12 levels
• Urinalysis

A variety of tests are also often implemented to help identify pathological brain changes and/or to rule out other causes. Examples include: ^{[1] [2] [6] [7]}

• Lumbar puncture (spinal tap): This collects a sample of the cerebrospinal fluid to analyze specific Alzheimer’s biomarkers
• Computed tomography (CT) scan: This can help identify brain atrophy
• Magnetic resonance imaging (MRI): This is more specific than a CT scan, and can identify atrophy or abnormalities in specific brain structures.
• Positron emission tomography (PT) scan: This can provide insight of dysfunction in smaller brain areas (some of which may not be detected by other methods)
• Includes amyloid and tau PET imaging

Your doctor may also implement a mental status test and perform neuropsychological testing to evaluate memory and other important cognitive skills and functions. Examples of these tests are: ^[8]

• Mini-State Mental Exam (MSME): An 11-question scale measuring five areas of cognitive function, such as recall and language.
• Ascertain Dementia 8 (AD8): This scale has 8 questions assessing key cognitive changes over the last several years, such as with judgment, memory, and learning.
• Montreal Cognitive Assessment (MOCA): This assessment consists of 11 different tasks that measure different aspects of cognitive function, such as memory, attention, and verbal fluency.

Coming to Terms with a Diagnosis

A diagnosis of Alzheimer’s disease can be very stressful and emotional for the individual and those who love and care for them. There is no cure for Alzheimer’s disease, and the average life expectancy after diagnosis is 4 to 8 years, although some people can live up to 20 years or longer, depending on various factors. ^{[1] [2]}

It’s important to take the time you need to fully process the diagnosis. Equally as important is communicating openly with your loved ones, and letting them know of any support you need.

Talk to your healthcare providers too, so you can learn as much as you can and know more about what to expect. And if you’re dealing with significant stress, anxiety, and other related issues, working with a mental health professional can help ease symptoms.

Treatment Options for Alzheimer’s Disease

At this time, there is no cure for Alzheimer’s disease, but some treatments may help to slow disease progression. Other treatments are implemented to manage symptoms and improve overall life quality and functioning ability.

Medication

Several medications may be useful for Alzheimer’s disease. Firstly, there are specific medications that may help reduce the cognitive symptoms of Alzheimer’s, including: ^{[1] [2] [7]}

• Cholinesterase Inhibitors: These help to boost acetylcholine, which helps enhance nerve cell communication. This may help with memory, learning, and general cognition. Commonly prescribed ones are:
• Donepezil
• Galantamine
• Rivastigmine
• Memantine: This drug blocks the activity of glutamate, which is elevated in Alzheimer’s and can damage nerve cells.

In addition, two specific medications are approved to help reduce amyloid plaque build-up: ^{[1] [2] [4] [7]}

• Lecanemab: This drug targets amyloid fibers before they clump together
• Donanemab: This drug targets amyloid plaques that have already developed

A variety of other medications may be used to help reduce comorbid conditions and symptoms. For example, your doctor may prescribe: ^{[1] [2]}

• Antidepressants: These may help with depression, anxiety, sleep issues, and mood instability.
• Antipsychotics: These drugs can help with paranoia, hallucinations, agitation, and aggression.
• Anti-seizure medications: These may help with mood changes and behavioral disturbances

Therapy

In addition to medication, certain therapies may be useful for managing symptoms and improving life quality. Specific therapies include: ^{[1] [5] [9]}

• Cognitive-behavioral therapy (CBT): This therapy can help address maladaptive thoughts and behaviors that cause distress. It may be useful for people with depression and anxiety, especially in the earlier stages.
• Psychotherapy/Counseling: General forms of psychotherapy and counseling can help individuals come to terms with their diagnosis and manage distress.
• Cognitive stimulation therapy (CST): This therapy involves themed weekly activity lessons that promote mental stimulation to keep one’s mind active.
• Cognitive rehabilitation: This involves specific skills training tailored to one’s needs, goals, and abilities. It helps to preserve cognitive functioning and ability.
• Creative arts therapies: These therapies can involve making music, playing an instrument, painting, and other creative outlets to stay engaged and promote better well-being.
• Reminiscence therapy: This involves talking about one’s past and sharing memories, often with the use of photos, music, or familiar/meaningful objects.

Other Treatments/Strategies

Other treatments or strategies may be implemented too, mainly to promote a healthier lifestyle, which can help manage symptoms. Examples include:

• Regular exercise
• Daily sunlight exposure
• Wind-down routine before bed (and other sleep hygiene practices)
• Adequate nutrition and hydration
• Staying in touch with family and friends
• Regular socialization

Managing Alzheimer’s Disease at Home

If you have Alzheimer’s disease, it’s important to take care of yourself and implement steps to make daily life more manageable. The following tips can help in managing Alzheimer’s disease at home: ^{[7] [9]}

• Keep keys, wallets, phones, and other important items in the same spot
• Make use of a calendar or whiteboard for daily scheduling
• Keep medicines in a secure location
• Set reminders for tasks or appointments
• Keep familiar objects and photos in the house
• Get rid of any clutter or unnecessary items
• Install handrails on stairs and in bathrooms
• Use alarm sensors, such as on doors and windows
• Establish consistent daily routines (e.g. bathing, dressing, meals)
• Make a list of emergency phone numbers
• Engage in enjoyable, lightly stimulating activities
• Implement healthy lifestyle practices, such as exercise, nutritious meals, and sufficient sleep

In milder and earlier stages of the disease, some (or even all) of these can be implemented by the individual with Alzheimer’s. As the disease progresses and symptoms worsen, caregivers should be the ones to ensure these management strategies are carried out.

Support for Caregivers

Caring for a loved one with Alzheimer’s can be stressful and emotional. If you’re a caregiver, it’s essential to take care of yourself too and get the support you may need. The following tips may help achieve this:

• Regular exercise
• Join a support group
• Practice stress management and coping strategies
• e.g. mindfulness, deep breathing, engaging in enjoyable/leisure activities
• Maintain regular eating and sleeping schedules
• Consider respite care
• Seek any counseling or mental health care, if needed

Author

Jack Cincotta

Jack Cincotta holds a M.S. degree in Psychology. He is also a board-certified holistic health practitioner through AADP and an AFPA-certified holistic health coach and nutritionist.

Activity History - Last updated: March 19, 2026, Published date: March 19, 2026

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Reviewer

Jennifer Brown

Dr. Jennifer Brown is dual board-certified in family medicine and obesity medicine. She currently works for Amwell Medical Group, providing virtual primary care services, including mental health treatment.

Activity History - Medically reviewed on April 15, 2026 and last checked on March 19, 2026