Dementia: understanding it

In the early stage, many people still live independently. They may drive, work and take part in social activities, while noticing memory lapses.

Changes people may notice

• Forgetting something just read
• Losing or misplacing things more often
• More trouble planning or organizing
• Trouble finding the right word or name

The middle stage is usually the longest and can last many years. Symptoms become clearer, and the person needs more help with daily life. Frustration or anger can show up, often because tasks have become hard.

Changes that may happen

• Changes in sleep
• Confusion about where they are or what day it is
• Forgetting parts of their own history
• Personality and behavior changes, like suspicion
• Wandering or getting lost

The Daily care & safety at home guide covers daily care in this stage in depth.

In the late stage, a person gradually loses the ability to hold a conversation, respond to their surroundings and, in time, control movement. They need help around the clock and can get infections more easily.

We don’t yet know for sure what can prevent dementia. But in 2024, a large expert group called the Lancet Commission estimated that about 45% of dementia cases could, in theory, be prevented or delayed if 14 risk factors were removed. That number is a model, not a promise.

The 14 risk factors the Commission named

• Air pollution
• Depression
• Diabetes
• Drinking too much alcohol
• Hearing loss
• High blood pressure
• High “bad” (LDL) cholesterol in midlife
• Less education in early life
• Not being physically active
• Obesity
• Smoking
• Social isolation
• Traumatic brain injury
• Untreated vision loss

Brain-friendly habits

• Get blood pressure, hearing and eyes checked
• Move your body most days
• Protect your head from falls and injuries
• Stay connected with friends, family and community
• Get support for low mood and protect your sleep

Everyone puts their keys down somewhere odd once in a while, then finds them. With dementia, things are misplaced often and the person can’t retrace their steps to find them. Sometimes they may believe someone took them.

Forgetting what day it is and remembering later is normal, especially on holidays or after retirement. With dementia, a person may lose track of the date or even the time of year, and get confused about time, people and places.

It’s normal to have a word on the “tip of your tongue.” With dementia, a person may have trouble following or joining a conversation, repeat the same questions, or use unusual words for familiar things.

Missing a monthly payment or making a bad choice now and then happens to everyone. With dementia, keeping up with bills becomes a regular problem, and poor judgment happens a lot of the time.

Making the odd error when managing money or household bills is common. A warning sign is when planning, following a familiar recipe or keeping track of monthly bills becomes a regular struggle.

Occasionally needing help with microwave settings or recording a show is normal. A warning sign is having trouble finishing everyday tasks you’ve done for years, like driving somewhere familiar, organizing a grocery list or remembering the rules of a favorite game.

Some vision changes, like cataracts, are common with age. For some people with dementia, though, changes in how the brain handles what they see cause trouble with reading or balance, or with judging distance, color or contrast, which can affect driving.

Everyone makes a poor choice now and then. A warning sign is a pattern of poor judgment, such as with money, or paying less attention to grooming and keeping clean.

Feeling uninterested in social plans sometimes is normal. A warning sign is pulling away from hobbies and social activities, sometimes because following conversations or keeping up with a favorite team has become hard.

Withdrawal can also be a sign of depression, which is common and treatable. Either way, it’s worth talking to a clinical provider.

Getting set in your ways and annoyed when routines change is common with age. A warning sign is becoming confused, suspicious, low, fearful or anxious, and getting upset easily at home, with friends, or when out of your comfort zone.

Changes in mood or behavior can appear before memory problems, especially in some types of dementia.

Memory problems can come from things other than dementia. Depression, stress, thyroid, kidney or liver problems, vitamin levels, some tumors, heavy alcohol use, and side effects of treatments can all cause dementia-like symptoms. Some of these can be treated, and the memory problems may improve.

Big life events matter too. Retirement, the death of someone close, or moving home can leave people feeling confused or forgetful for a while. This usually improves as the stress and emotions settle.

Some older adults have more memory or thinking problems than other people their age but can still take care of themselves and handle daily tasks. Doctors call this mild cognitive impairment, or MCI.

MCI can sometimes be an early sign of dementia, but not always. That’s why regular check-ins with a clinical provider matter. People with memory problems are often advised to have their memory checked every 6 to 12 months.

Alzheimer’s disease is the most common cause of dementia, making up about 60–70% of cases worldwide. In the brain, abnormal clumps of proteins (called amyloid plaques and tau tangles) build up and harm brain cells.

It often starts with trouble remembering recent events and conversations. Over time, it can affect language, planning, finding your way, and eventually daily care.

Vascular dementia happens when conditions damage blood vessels in the brain or cut off the flow of blood and oxygen to it, for example after a stroke or many small strokes.

Because it’s linked to blood vessels, looking after heart health, like keeping blood pressure in a healthy range, is one way people try to protect their brain.

Lewy body dementia is caused by abnormal deposits of a protein (alpha-synuclein) called Lewy bodies. Along with thinking changes, people may have problems with balance and movement, and some see or hear things that aren’t there.

Frontotemporal dementia is rare and tends to happen in people younger than 60. It affects the front and side parts of the brain, which manage behavior, personality and language.

Because the first changes are often in behavior, like acting on impulse or seeming not to care about others’ feelings, FTD can be mistaken for a mental health or relationship problem at first.

Studies of older adults’ brains after death show that many people with dementia had more than one type of brain change at once, such as Alzheimer’s plus vascular changes.

Researchers have also described a newer type called LATE, which causes Alzheimer’s-like symptoms and tends to affect people over 80.

Other conditions that can cause dementia or dementia-like symptoms

• Chronic traumatic encephalopathy (CTE), caused by repeated head injuries
• Creutzfeldt-Jakob disease, a rare brain disorder
• Heavy alcohol use over a long time
• Huntington’s disease, an inherited brain disease
• Normal pressure hydrocephalus, a buildup of fluid in the brain, which often improves with treatment

For more on concussion and head injury, see the Brain injury & concussion guide.

People with Down syndrome have an extra copy of chromosome 21, which carries a gene (APP) linked to Alzheimer’s. Estimates suggest that 50% or more of people with Down syndrome will develop Alzheimer’s, with symptoms often appearing in their 50s and 60s.

Because dementia is less expected in younger adults, changes in memory, behavior or planning can be put down to other causes at first. Some types, like frontotemporal dementia, often start with behavior or language changes rather than memory.

What can help

• Ask whether a specialist, such as a neurologist, should be involved
• Bring someone who knows you well to appointments
• If you can’t find a specialist nearby, ask about the nearest medical school’s memory or dementia clinic
• Write down specific changes, with dates and examples

When a parent or partner has younger-onset dementia, the whole family is affected. Kids may notice changes before anyone explains them. Simple, honest words help children feel safer than silence.

Ideas for families

• Find time for the things you still enjoy together
• Keep routines as steady as you can
• Remind children it’s not their fault, and it’s not catching
• Use simple words: “Dad has an illness in his brain that makes it hard to remember”

The “Sharing dementia care: family, kids & care staff” guide has a section on explaining dementia to kids and teens.

An early diagnosis gives time to plan, while the person can still take part in decisions about money, work, and future care. Advance care planning can give a sense of control over an uncertain future.

Things people often plan for

• Legal and money plans, made while the person can take part
• Naming someone to make health decisions if needed
• Talking with an employer about changes at work
• Writing down wishes for future care

The Alzheimer’s Association 24/7 Helpline (1-800-272-3900) can help with care planning, legal and money questions, and local resources.

Up to 40% of people living with Alzheimer’s may have significant depression, most often in the early and middle stages. It can look different than usual: less talk of sadness, and more loss of interest, pulling away from people, or tiredness.

What can help

• Exercise together, especially in the morning
• Keep a predictable daily routine
• Reassure them they will not be abandoned
• Schedule enjoyable activities, people and places more often

A person with dementia may get upset, worried or angry more easily, pace, or even lash out. Pain, hunger, thirst, poor sleep, noise or feeling rushed can all play a part.

What can help

• Be patient, and try not to argue
• Check for pain, hunger, thirst or a need for the bathroom
• Redirect gently to music, a book or a short walk
• Speak softly and slow down. A calm voice is catching

Many people with dementia become more confused, anxious or restless as the day ends. This is often called “sundowning.” Tiredness after a busy day, a mixed-up body clock and dim light that makes shadows confusing can all play a part.

What helps

• Get some daylight outside each day
• Keep a steady daily routine for waking, meals and bedtime
• Keep evenings calm: less TV, noise and chores
• Plan outings, appointments and bathing for the morning or early afternoon
• Turn lights on before it gets dark

Some people with dementia hide things, or believe others are hiding or taking things. They may feel suspicious or threatened for little reason, misunderstand what they see or hear, or see things that aren’t there.

What can help

• Don’t argue about what is real. Respond to the feeling instead
• Keep spare sets of things that often go “missing”, like glasses or keys
• Reduce clutter, noise and confusing mirrors or shadows
• Tell their clinical provider, to check for other causes

Wandering and getting lost is common, and many people do it more than once. It can happen in any stage, especially at times of day when a person feels restless.

Ways to lower the risk

• Keep a recent photo handy, and a list of places they might go
• Keep them active during their restless times
• Make sure they carry ID or wear a medical bracelet
• Meet basic needs like toileting, meals and drinks

Too much going on at once can be overstimulating for someone with dementia: noise, clutter, crowds, or a house full of visitors they don’t recognize. Unfamiliar surroundings and feeling lost can add to the stress.

People with dementia can also pick up on the stress of those around them, so a rushed or frustrated carer can unintentionally add to the upset.

What helps

• Bring familiar things, like photos or favorite music, to new places
• Clear clutter and keep things in the same spots
• Keep gatherings small, or offer a quiet room to step away to
• Slow down and speak softly

As dementia changes the brain, a person may not be able to say “my tooth hurts” or “I’m thirsty.” Instead, the discomfort can show up as agitation or even aggression. Infections, tiredness from poor sleep, and clothes that are too tight or wrong for the weather can do this too.

What helps

• Ask yourself first: could they be in pain?
• Check clothing, temperature and comfort
• Offer a drink, a snack or a trip to the bathroom

Specialists you might see

• A geriatric psychiatrist, who specializes in older adults’ mental and emotional health and can assess memory and thinking
• A geriatrician, who specializes in the health of older adults
• A memory clinic, where a team works together
• A neurologist, who specializes in the brain and nervous system and can review brain scans
• A neuropsychologist, who does detailed tests of memory and thinking

Before the early 2000s, the only sure way to know someone had Alzheimer’s was after death. Now, lab and imaging tests can show biological signs, called biomarkers, in a living person.

In some places, doctors can order a blood test that measures a protein linked to Alzheimer’s. But a blood test alone should not be used to diagnose dementia. It may be considered alongside other tests, and availability is still limited.

Your doctor should ask whether you want to know your diagnosis. Unless you decide otherwise, they should talk with you, and your family if you wish, about what it means.

You should be told about

• How it may affect driving or work
• Support services and groups near you
• The symptoms and how things might change
• The type of dementia, or a plan to reassess if it isn’t clear yet
• Treatment options
• Where to get money and legal advice
• Who will coordinate your support

Dementia usually develops slowly. A sudden state of confusion, often during an illness or a hospital stay, is called delirium. It can cause dementia-like symptoms and needs medical attention.

It’s okay to take time to feel sad, mourn and grieve the changes in your life. Recognizing your feelings is the first step to coping with them. No two people deal with a diagnosis in exactly the same way.

Ways to work through it

• Join an early-stage support group, in person or online
• Keep doing activities you enjoy, for as long as you can
• Talk with a counselor, or a faith leader you trust
• Write your thoughts and feelings in a journal

Sharing your diagnosis with close family and friends can help them understand and support you. Speak openly and honestly. Expect that they may need time too, since they may be struggling with the news.

Words you could use

• “Here’s what helps me: give me a little more time to answer.”
• “I’d love it if we kept our weekly walk going.”
• “I’ve been diagnosed with early dementia. I’m still me.”
• “Please don’t finish my sentences unless I ask.”

In the early stages, many people continue with their everyday activities. As things change, new strategies help them adapt, like reminders, routines and asking for help with specific tasks.

Ideas that help

• Focus on what you can still do, not only on what has changed
• Keep a simple daily routine
• Stay active and social
• Think about a legacy project: a memory book, recorded stories, letters to loved ones
• Use calendars, notes and phone reminders

For practical next steps, like memory aids, work, driving, planning ahead and support groups, see the Living with early dementia guide.

In the early stage, many people can still talk and join in fully. Don’t assume what someone can or can’t do just because of a diagnosis. Dementia affects each person differently.

Try this

• Ask what they’re still comfortable doing, and where they’d like help
• Give them time to answer, and don’t interrupt unless they ask for help
• Speak to the person directly, not just to the person with them
• Stay in touch. Don’t pull away
• Use humor when it lightens the mood
• Use the way of talking they prefer: in person, phone or messages

In the middle stage, conversations may need more patience. Short, simple sentences and a calm space make it easier to follow along.

Try this

• Ask one question at a time
• Don’t argue. If you disagree, let it go
• Don’t correct or criticize. Listen for the meaning behind the words
• Offer yes-or-no choices: “Would you like coffee?” instead of “What would you like to drink?”
• Show, don’t just tell: give step-by-step instructions and use written notes
• Speak slowly and clearly, and keep eye contact
• Talk one-on-one in a quiet place

In the late stage, words may be few. But connection is still possible. The feelings behind sounds and expressions often matter more than the words.

Try this

• Approach from the front and say who you are
• If you don’t understand, ask them to point or gesture
• Treat them with dignity. Never talk about them as if they aren’t there
• Use touch, music, familiar smells and tastes

Your patience, presence and practical help make a real difference. Changes in mood or behavior usually come from the illness, not from who they really are.

Ways to help

• Celebrate small wins
• Give them choices and as much control over daily life as you safely can
• Go with them to appointments and help write down questions
• Keep routines steady and surprises few
• Learn about dementia from trusted sources

Caring for someone with dementia can be exhausting and lonely. Nearly 13 million Americans give unpaid dementia care, so you are far from alone. Counseling or a support group for family members can help you carry the load.

The Caring for yourself as a dementia carer guide covers respite, burnout and grief in depth, and the Caring for yourself as a long-term carer guide helps with the long haul.

About one-third of people age 85 or older may have some form of dementia, but many people live into their 90s and beyond without any signs of it. Dementia is caused by disease in the brain, not age alone.

Dementia describes a group of symptoms that get in the way of daily life. Alzheimer’s is a specific brain disease, and the most common cause of dementia. See “Types of dementia, in plain words” above.

Dementia-like symptoms can come from depression, sleep apnea, delirium, thyroid problems, low vitamin levels, alcohol use and side effects of some treatments. Many of these can be reversed with the right care.

An early diagnosis helps people plan, get support, find treatable causes of symptoms, and keep doing what matters. Support groups, counseling, routines and community all make a difference.

Even when words fade, people respond to touch, music, familiar smells and the feeling behind your voice. Your presence matters.

Younger-onset dementia affects people under 65, including some in their 30s, 40s and 50s. See “When dementia comes early” above.

Before the early 2000s, the only sure way to confirm Alzheimer’s was after death. Today, doctors use health history, memory tests, brain scans and biomarker tests to diagnose it in living people.

Having a parent or sibling with Alzheimer’s does raise your risk. But in most cases there is no single genetic cause, and many people who get it have no family history at all.

Only a few rare gene changes cause Alzheimer’s directly, usually before 65. The Protect your brain for life guide explains genes in plain words, and what you can do.

A healthy diet and lifestyle may lower risk. But no single food or product has been proven to prevent, treat or cure dementia. Be careful with anything that promises it can.

Stigma can stop people from

• Building a support system
• Getting an early diagnosis, or any diagnosis at all
• Living the best life they can while they’re able
• Making plans for their future
• Seeing a doctor when symptoms start
• Taking part in research

Experiences people describe

• Family who won’t talk about it, or assume life is over
• Friends who don’t believe the diagnosis, or drift away
• People asking your partner how you are, instead of asking you
• Younger people being told they’re “too young” to have dementia

What helps

• If someone thinks dementia is just normal aging, see it as a chance to educate
• Share accurate information, like a trusted leaflet or website
• Stay connected with family, friends or a support group
• Talk openly about dementia, and about the need for better treatment and care
• Use your voice: people living with dementia are the most powerful advocates

Try this

• Ask what they still enjoy, and do it together
• Gently correct myths when you hear them
• Keep inviting them. Don’t wait for them to ask
• Speak to the person directly, not just to the person with them

The Alzheimer’s Association runs a free, confidential Helpline that answers around the clock, 365 days a year. Anyone can call: people living with dementia, caregivers, family and the public.

They can help with

• Care planning and finding local programs
• Caregiver stress
• Legal and money planning
• Next steps after a diagnosis
• Safety concerns
• Understanding and responding to behavior changes

Help is available in more than 200 languages. TRS users can dial 711. Staff can’t diagnose, so see a clinical provider for medical questions.

Early-stage dementia support groups help people share what they’re going through with others who understand. Groups for family members can ease stress and loneliness.

Where to look

• Ask at your local senior center or place of worship
• Ask your clinical provider
• Call the Helpline above for local groups
• Look for online communities run by trusted organizations

Staying active and socially engaged supports both memory and mood. Many communities have memory cafés, choirs, art groups, walking groups or volunteer roles that welcome people living with memory changes and their families.

Neighbors, friends and faith communities can also help with small things: a ride, a meal, a visit, or an hour so a caregiver can rest.

Alzheimer’s Disease International has 105 member associations around the world, one per country. Visit alzint.org to find the association in your country.

For emotional support or a crisis, findahelpline.com lists free, confidential support lines by country.