Alzheimer's + dementia, explained clearly
Independent, referenced reporting on memory symptoms, diagnosis, blood tests, brain scans, medicines, risk and care.
The current picture
Reviewed 19 September 2026
A proper assessment combines the story of change, daily function, cognitive testing, medicines, mood and sleep, blood tests and often brain imaging. Biomarkers may help selected people.
Use the memory concerns checkSome medicines treat symptoms. Anti-amyloid medicines may slow progression for selected people with early Alzheimer's, but require specialist assessment and monitoring.
Compare treatment pathsThey can support specialist evaluation, but availability, interpretation and confirmatory requirements differ. A blood test is not a stand-alone home diagnosis.
Blood-test guideThe map
Normal, BCI or MCI?
The phrase benign cognitive impairment (BCI) is sometimes used informally for stable or subjective concerns, but it is not a single universally standardised diagnosis. Clinicians more often distinguish normal ageing, subjective cognitive decline and mild cognitive impairment (MCI).
Occasionally misplacing something or taking longer to retrieve a name can occur with age, especially when tired or stressed. The information often returns later, and everyday independence remains intact.
The person feels less sharp, but brief testing and daily function remain broadly normal. Sleep, mood, medicines, hearing, alcohol and health conditions still deserve review. Persistence or progression should not be dismissed.
Memory or thinking is measurably affected, but independence is largely preserved. MCI is not dementia and does not always progress, but it warrants assessment and follow-up.
Changes persist or progress; other people notice them; appointments, medicines, bills, navigation, language or familiar tasks become harder; behavior changes; or there are vascular risks, previous stroke, head injury or a strong family history.
A history from the person and someone who knows them, medication and mood review, neurological examination, validated cognitive testing, blood and urine tests, hearing and vision review, and CT or MRI when clinically appropriate. PET or fluid biomarkers answer narrower specialist questions.
Terms such as cerebral atrophy, volume loss or white-matter change describe appearances, not a diagnosis by themselves. Some degree of volume loss occurs with ageing, and a person may have noticeable changes on imaging without significant cognitive impairment.
The reverse is also possible: CT or routine MRI may look normal or show only mild change while the person has genuine MCI or dementia, particularly early in the illness. The important question is whether the pattern, symptoms, cognitive testing and change in daily function fit together.
Without sudden change, focal neurological signs or another urgent concern, imaging is commonly arranged as an outpatient investigation. Public specialist and memory-clinic pathways can involve substantial waits that vary by state, service and location. Private imaging may be faster, but referral rules, Medicare eligibility and out-of-pocket costs vary; MRI often requires specialist involvement for a Medicare rebate.
Sudden confusion, weakness, facial droop, speech difficulty, seizure, severe new headache or rapid decline is not a routine waiting-list problem and needs urgent assessment.
Delirium begins suddenly and often fluctuates. Anaesthetic and pain medicines, infection, low oxygen, dehydration, pain, constipation or urinary retention, metabolic disturbance and alcohol or medicine withdrawal are among the causes clinicians should assess promptly.
An episode may resolve when the trigger is treated, but it can also reveal reduced cognitive reserve or previously unrecognised neurological illness. Persistent symptoms deserve follow-up after the acute illness has settled.
CT or MRI is not mandatory for every uncomplicated postoperative delirium. Imaging should be considered urgently with focal neurological signs, head injury, seizure, severe headache, reduced consciousness or suspected stroke or bleeding, and should be reconsidered when delirium remains unexplained or does not improve as expected. The threshold should be especially low after a fall or head impact in someone taking an anticoagulant or other blood thinner.
A confused, delirious or memory-impaired person may be unable to remember or explain an unwitnessed fall or head impact. There may be no scalp bruise or other visible injury. New drowsiness, headache, imbalance, weakness, speech change, vomiting or otherwise unexplained deterioration should increase concern for intracranial bleeding and prompt urgent clinical assessment.
In that situation, an accessible Anonamed profile may help clinicians quickly identify blood thinners, other medicines and medical conditions when the person cannot provide the information themselves. Anonamed is deliberately anonymous for hacking protection and safer public display on a locked phone; it does not store emergency contacts. Named emergency contacts may instead be available through a separately configured device feature such as Apple Medical ID in the Health app, or on a clearly marked note or emergency card kept in the person's wallet. A wallet card can also carry the anonymous Anonamed QR code so responders can reach the medical profile without unlocking the phone. An accessible advance care directive may also communicate treatment preferences and limitations. Clinicians still need to confirm the applicable document and local legal requirements.
This can provide an extra safety layer for people with early dementia or MCI who remain independent and want to go out or travel alone, or who may become separated from a family group, organised tour or cruise excursion. The plan can combine the anonymous medical QR profile with a separate emergency-contact card, current itinerary and agreed check-in arrangements. Anonamed itself is not a location tracker and does not identify the person.
Australian sources: Dementia Australia on MCI, testing and diagnosis, and the Australian Government dementia pathway.
A clinician's clue, not a verdict
The person must understand the instruction, remember what a clock looks like, plan the circle, arrange 12 numbers in sequence and in the correct spaces, then translate a stated time into two hands of different lengths.
Crowding all the numbers on one side can suggest difficulty judging space or planning ahead. Missing or repeated numbers may reflect attention, sequencing or memory problems. Incorrect hands may show difficulty understanding or holding the requested time in mind.
One unusual clock does not diagnose dementia or show that a person has lost every ability. Vision, movement, language, education, anxiety, stroke, delirium and misunderstanding can all affect the result. Clinicians interpret it with history, daily function and other tests.
Private on this device
This is not a dementia test and does not calculate a diagnosis or risk score. It simply helps organize changes worth discussing with a clinician. Nothing is submitted or stored.
Sudden confusion, new weakness, facial droop, severe headache, seizure, head injury, fever or a rapid change over hours or days may be an emergency.
Treatment
Cholinesterase inhibitors and memantine may help symptoms or function for some people. They do not remove the underlying cause.
Lecanemab and donanemab are used for selected patients in the early symptomatic stages with confirmed amyloid. Benefits are modest and monitoring for ARIA is essential.
Medication review, vascular health, hearing, mood, sleep, activity, caregiver support and advance planning remain central to care.
Do not start, stop or change prescribed medicine based on this site. Availability and approval differ by country.
Inside the evidence
Structural MRI or CT can look for stroke, bleeding, tumors, hydrocephalus and patterns of brain volume loss. PET can measure glucose metabolism or selected disease-related proteins. A scan must be interpreted in clinical context.
Editorial standard
Anonamed separates established guidance from emerging research. Articles should identify the review date, link to primary or authoritative sources, disclose uncertainty and avoid presenting screening as diagnosis.