10 Warning Signs of Alzheimer's Disease You Shouldn't Ignore

Alzheimer's disease rarely announces itself. It is usually a family member — a spouse, an adult child, sometimes a neighbor — who first notices something is different. The person themselves often doesn't see it, or explains it away. This is a walk-through of the ten warning signs that most commonly show up in the earliest stages of Alzheimer's disease, written in plain English, with the distinction between them and normal aging spelled out.

These signs are adapted from widely published criteria used by the Alzheimer's Association and the National Institute on Aging. One or two of them in isolation are rarely cause for alarm. Several of them, together, sustained over months, in a person who did not used to have them, is what matters.

1. Memory loss that disrupts daily life

Forgetting a name and having it come back an hour later is normal. Forgetting an appointment you made last week, then asking about it again twice in the same conversation, and relying increasingly on sticky notes and reminders, is not.

The clearest version of this sign: a person who used to rely on their own memory is now heavily dependent on calendars, phones, and family members to keep track of recent events.

2. Difficulty planning or solving problems

Tasks that involve multiple steps become harder. A recipe that was once effortless takes three tries. Keeping the checkbook in order slips. Following a plan — the month's bills, a home repair sequence, packing for a trip — produces confusion.

Normal aging may slow someone down on unfamiliar problems. Alzheimer's often affects the familiar multi-step tasks that used to be automatic.

3. Trouble completing familiar tasks

A lifelong cook forgets the order of steps in a recipe they've made for forty years. A driver gets disoriented on a familiar route. A bookkeeper struggles with a monthly reconciliation they've done hundreds of times.

The key word is familiar. Struggling with new technology is aging; struggling with the toaster is not.

4. Confusion with time or place

Losing track of days of the week occasionally is normal. Losing track of the season, the year, or how you got to the place you're currently standing is not.

People in early Alzheimer's sometimes forget where they are in the middle of an errand. Some develop the sense that it is an earlier time in their life — calling for a parent who died decades ago, for example.

5. Trouble understanding visual images and spatial relationships

This is the sign families most often miss because they interpret it as "vision problems." It isn't about acuity. It is about spatial processing: judging distance, recognizing faces, reading, or handling objects that require depth perception.

A common early symptom: trouble with reading long passages that used to be easy. Another: misjudging the edge of a curb or step.

6. New problems with words, spoken or written

Everyone pauses occasionally to find a word. The version that is a warning sign is losing the thread of a conversation mid-sentence, calling familiar things by the wrong word ("that round thing on the wall" for clock), or struggling to follow dialogue at a dinner table.

Handwriting sometimes deteriorates independently. A letter that used to be clean becomes hard to read, even when the person is physically capable.

7. Misplacing things and losing the ability to retrace steps

The test is not whether someone loses their keys. The test is what happens next.

• Normal: loses keys, retraces the last hour, finds them.
• Warning sign: loses keys, cannot reconstruct the morning, finds them in an unexpected place (freezer, mailbox, a different coat pocket), and has no memory of putting them there.

Over time, people with Alzheimer's sometimes begin to believe that items are being stolen or moved by others. This is often the most distressing sign for families.

8. Decreased or poor judgment

Large, uncharacteristic financial decisions are the classic example — falling for a telemarketer or a scam email, giving a disproportionate gift to a stranger. Less obvious versions: paying less attention to personal hygiene, wearing clothes inappropriate for the weather, or making decisions that feel fundamentally unlike the person.

Judgment changes are subtle and often denied by the person experiencing them. A trusted family member's observation usually matters more than self-report here.

9. Withdrawal from work, hobbies, or social activities

A retired teacher stops reading. A lifelong golfer stops going to the course. Someone who loved dinner parties declines invitations.

This sign is often misread as depression (and the two genuinely overlap). A clinician can help separate cognitive withdrawal from mood-driven withdrawal. Both are worth treating.

10. Changes in mood or personality

A normally even-tempered person becomes irritable or suspicious. A gregarious person becomes withdrawn. Someone with no history of anxiety becomes anxious in unfamiliar settings.

This is particularly common in earlier stages and may actually precede clear memory signs. Family members often describe it as: "She's just not herself lately."

When one or two of these show up

Don't panic. Every person on earth has some of these in mild form some of the time. The pattern that matters is:

• Several signs together, not just one.
• Sustained over weeks to months, not a single bad week.
• In a person who did not previously have them. Baseline matters.
• Interfering with daily function. Managing medications, driving, cooking, finances.
• Noticed by others, not only by the person.

If the pattern fits, schedule a visit with a primary care physician. Bring a list of the signs, with dates. Bring a family member. A screening like the clock drawing test can be a useful first look at home, but a clinician's evaluation is what separates Alzheimer's from the many treatable conditions that can mimic it.

Why an early conversation matters

Alzheimer's is a progressive disease, and the interventions we have — medications, lifestyle modifications, safety planning, caregiver support — work better the sooner they start. Early also matters for non-medical reasons: financial planning, legal documents, and family conversations are all easier to have while the person can meaningfully participate.

For a deeper look at how to tell these warning signs apart from normal aging, see our signs vs normal aging guide.

Related reading

• Early Signs of Dementia vs Normal Aging
• Dementia vs Alzheimer's: What's the Difference?
• The Clock Drawing Test: Complete Scoring and Interpretation Guide
• What to Do After a Low Clock Drawing Test Score

References

• Alzheimer's Association. 10 Early Signs and Symptoms of Alzheimer's. alz.org.
• National Institute on Aging. Alzheimer's Disease Fact Sheet. nia.nih.gov.
• Livingston G, Huntley J, Sommerlad A, et al. Dementia prevention, intervention, and care: 2020 report of the Lancet Commission. The Lancet. 2020;396(10248):413–446.

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Disclosure: Dr. Shimada is the founder of Tokei Health. This article is informational and is not a substitute for individual medical advice from your own clinician.