Memory and forgetfulness in older age: what is normal and what is not
Forgetting a name, walking into a room and losing the thread, or needing longer to recall a word are normal parts of getting older, and on their own they are not signs of dementia. What matters is the pattern: occasional lapses that do not stop you living your life are usually age-related, whereas memory that is getting steadily worse over months and starting to interfere with everyday tasks is worth checking. Many causes of worsening memory are treatable, so the most useful thing you can do is see your GP rather than wait and worry.
Key facts
- Dementia is not a normal part of ageing. It is a syndrome caused by diseases that damage the brain, and it is distinguished from ordinary forgetfulness by a noticeable decline over months that erodes your ability to manage daily life.1
- In community studies, the large majority of people who complain about their memory turn out to have normal scores on objective testing, which is genuinely reassuring for most worried readers.2
- The 2024 Lancet Commission estimates that around 45 percent of dementia worldwide is potentially preventable by addressing 14 modifiable risk factors across life, with untreated hearing loss the single largest midlife factor.3
- Several causes of memory trouble are reversible, including low vitamin B12, an underactive thyroid, depression, certain medicines, poor sleep and untreated hearing loss, which is why a basic check-up is worth having.45
What normal age-related memory change looks like
The ageing brain slows down a little, much as the rest of the body does. It takes a touch longer to take in new information, to summon a name you rarely use, or to switch quickly between tasks. This is ordinary, and it does not snowball into an inability to cope. The Alzheimer's Society puts it plainly: if a memory problem is mildly annoying but does not affect your ability to do things in everyday life, it is unlikely to be a sign of dementia.1
Common, normal features of an older memory include forgetting the names of people you do not know well, misplacing everyday items such as keys or glasses but being able to retrace your steps, occasionally missing an appointment, struggling for the right word during conversation, and needing a little longer to think things through.1 Stress, tiredness, doing three things at once and simply having decades more to remember all add to this. None of it points to a failing brain.
A helpful rule of thumb: forgetting where you parked is normal, while forgetting that you drove there is not. Forgetting a name and recalling it later is normal; struggling to recognise a close friend is not. It is the kind of forgetting, and whether it is getting worse, that matters more than the fact of forgetting itself.
Mild cognitive impairment: the middle ground
Between normal ageing and dementia sits a recognised stage called mild cognitive impairment, or MCI. Here, memory or thinking is measurably weaker than expected for someone's age and education, enough to show up on testing and to be noticed, but not yet enough to take away independence. People with MCI generally still manage their own finances, medicines and daily routines.
MCI matters because it raises the odds of later dementia, but it is not a sentence. Conversion to dementia runs at roughly 10 to 15 percent a year in specialist clinic populations and considerably lower, around 4 to 6 percent a year, in community samples.6 Just as importantly, a meaningful share of people with MCI stay stable or even return to normal cognition over time, particularly when a reversible contributor such as low mood, a thyroid problem or a sedating medicine is found and put right.6 In other words, MCI is a reason to investigate and to act, not a reason to despair.
Evidence note: the wide range in reported MCI-to-dementia conversion rates reflects how the people were recruited. Memory-clinic figures are higher because those patients were referred for a reason; community figures are lower and are closer to what a generally well older adult faces. Treat any single percentage with caution and focus on the trend in your own function.
Dementia warning signs worth acting on
The features that should prompt a conversation with your GP are not the odd lapse but a consistent, worsening pattern that gets in the way of normal life. Because it can be hard to judge this in yourself, the views of people close to you carry real weight.1 The table below adapts the Alzheimer's Society comparison of typical ageing against possible dementia.
| Area | Common sign of ageing | Possible sign of dementia |
|---|---|---|
| Memory for new information | Forgetting something told a while ago, but able to recall it with a prompt | Forgetting something just told, and asking the same question repeatedly |
| Everyday objects | Mislaying keys or glasses, then retracing your steps to find them | Putting items in odd places, such as keys in the fridge |
| Planning and money | Being a little slower, and occasionally slipping up with a new process | Struggling to follow a plan, or to manage regular bills and budgets |
| Language | Occasionally hunting for a word, mainly when distracted | Frequent word-finding trouble, and difficulty following conversation |
| Orientation | Briefly muddling the day, then quickly realising | Losing track of dates or seasons, or getting lost in a familiar place |
| Mood and interest | Sometimes reluctant to join in, but coping with change | Withdrawing from hobbies and friends, or marked changes in mood or personality |
One pattern deserves emphasis. A change that develops noticeably over weeks to months, rather than gently over many years, is more concerning and is worth raising sooner.1 So is memory loss accompanied by other new problems, such as difficulty with familiar tasks, confusion, or changes in behaviour. If any of this sounds familiar, the right next step is a GP appointment, not a self-diagnosis. The same habit of reading the whole picture rather than a single symptom runs through our wider health library.
Reversible causes worth checking first
This is the part that turns worry into action. A number of common, treatable conditions can blunt memory and concentration, and several mimic dementia closely enough that they are sometimes mistaken for it. The NHS lists stress, anxiety, depression and insomnia among the everyday treatable causes of memory problems, and notes that treatment tends to work better when started early.4 Before anyone assumes the worst, these are the things a sensible work-up looks for.
- Medicines. Several widely used drugs can fog thinking, especially in older people and especially in combination. Strongly anticholinergic medicines (some older antihistamines, bladder drugs and tricyclic antidepressants), as well as sedatives and sleeping tablets, are common culprits. A medication review is one of the simplest wins. If you take several drugs and want to map them out before that review, our stack builder can help.
- Vitamin B12 and folate. Low B12 is a classic, very treatable cause of cognitive and neurological symptoms, and it is more common with age. A blood test is routine, and our guide to B12 and folate deficiency explains why a result in the normal range does not always settle the question.5
- Thyroid. An underactive thyroid slows the body and the mind, and can closely resemble dementia in older adults. It is corrected with replacement hormone and is checked on the same blood panel.5
- Depression and anxiety. Low mood can dampen attention and recall so convincingly that it has been called pseudodementia. Crucially, the cognitive symptoms usually improve when the depression is treated.45
- Sleep. Poor or broken sleep, including untreated sleep apnoea, undermines the consolidation of memories and shows up as daytime forgetfulness and brain fog.4
- Alcohol. Regularly drinking above guideline levels impairs memory and, over years, can cause lasting damage. Cutting back often brings noticeable improvement.3
- Hearing loss. Straining to hear leaves less mental capacity for remembering, and untreated hearing loss is now the largest single midlife risk factor in the Lancet Commission analysis.3
Please do not stop or change any prescribed medicine on your own because you suspect it is affecting your memory. Sudden withdrawal of some sleeping tablets, sedatives or antidepressants can be harmful. Raise it with your GP or pharmacist, who can review the balance of benefit and risk and adjust things safely.
The evidence on protecting your memory
The encouraging headline is that a large slice of dementia risk is not fixed. The 2024 Lancet Commission, led by Gill Livingston and colleagues, concluded that around 45 percent of dementia cases worldwide are potentially preventable by tackling 14 modifiable risk factors across the life course.3 Population-level potential is not the same as a personal guarantee, and the underlying evidence is largely observational, but the direction of travel is consistent and the steps are good for the rest of the body too.
| Risk factor | Life stage | Approx. share of dementia risk |
|---|---|---|
| Hearing loss | Midlife | 7 percent |
| High LDL cholesterol | Midlife (new in 2024) | 7 percent |
| Less education | Early life | 5 percent |
| Social isolation | Later life | 5 percent |
| Untreated vision loss | Later life (new in 2024) | 2 percent |
| All 14 factors combined | Across life | About 45 percent |
The rest of the Commission's list includes high blood pressure, smoking, obesity, physical inactivity, diabetes, depression, traumatic brain injury and air pollution.3 Several of these are worth singling out because the evidence behind them is stronger or more actionable.
Hearing
The case for treating hearing loss has firmed up. In the ACHIEVE randomised trial, 977 adults aged 70 to 84 with untreated hearing loss were given either hearing aids and audiology support or a health education programme. Across the whole group there was no significant difference in three-year cognitive change, but in the subgroup at higher risk of decline, hearing intervention slowed cognitive decline by about 48 percent.7 That is a single trial with a mixed overall result, so it is best read as promising rather than settled, but getting your hearing checked and treated is low-risk and worthwhile in its own right.
Exercise
Physical activity is among the most consistently supported levers. A Cochrane review of aerobic exercise trials in older people without dementia found benefits for aspects of cognition such as attention and processing speed, although the authors judged the overall evidence modest and called for larger trials.8 The practical message is uncontroversial: regular movement, ideally including activity that gets you mildly out of breath, supports the brain as well as the heart. You can see how it fits with the broader machinery of ageing in our overview of the science of healthspan.
Mental and social engagement
Staying mentally and socially active is linked with better cognitive ageing, and loneliness and social isolation appear on the risk list for good reason.3 The strongest test of combining lifestyle changes is the Finnish FINGER trial, in which 1,260 at-risk older adults were randomised to a two-year programme of diet, exercise, cognitive training and management of vascular risk, or to general health advice. The intervention group did better on overall cognition, a modest but real benefit from a realistic package of changes.9
Blood pressure and vascular health
Keeping blood pressure, cholesterol and blood sugar in check protects the small vessels that supply the brain, which is why hypertension and, newly, high LDL cholesterol feature in the Commission's model.3 These are measurable, treatable and already part of standard NHS health checks.
Evidence note: most of the protective links above come from observational studies and from prevention trials in people at risk, not from proof that any single change will stop dementia in a given person. FINGER and ACHIEVE are the strongest randomised signals, and both are encouraging rather than definitive. The honest summary is that these habits tilt the odds in your favour and are worth doing regardless.
Seeking a UK memory assessment through your GP
If memory problems are affecting day-to-day life, or if those around you are worried, the NHS advice is straightforward: see your GP.4 It is often nothing serious, and where treatment is needed it tends to work better when started early. There are around 982,000 people living with dementia in the UK and more than a third do not yet have a diagnosis, so a timely assessment also opens the door to support that many people miss.10
At the appointment, the GP will ask about the problems and their timeline, and it helps to bring someone who knows you well. They will usually carry out a short, validated memory and thinking test in the surgery, and arrange blood tests to look for the reversible causes above. NICE guidance recommends exactly this sequence of brief cognitive testing plus blood tests to exclude treatable contributors before any referral.11 If needed, the GP refers you to a local memory assessment service or clinic for a fuller assessment, which may include more detailed testing and sometimes a brain scan.411 If you would like to walk in prepared, our start guide covers how to get the most from a GP visit.
- My memory has changed over the past several months: can we work out whether this is normal ageing, mild cognitive impairment or something that needs a referral?
- Can we check the treatable causes, including B12 and folate, thyroid function, mood, sleep and my current medicines?
- Could any of my prescriptions be affecting my memory, and is a medication review worthwhile?
- Should I have my hearing, vision, blood pressure and cholesterol checked as part of protecting my memory?
- If a referral is needed, what does the local memory assessment service involve and how long is the wait?
References
- Alzheimer's Society. Do I have dementia? Signs and symptoms versus normal ageing. 2026. alzheimers.org.uk.
- Cappa SF, et al. Subjective cognitive decline: memory complaints, cognitive awareness, and metacognition. Alzheimer's & Dementia. 2024;20(10). PMC11497716.
- Livingston G, Huntley J, Liu KY, et al. Dementia prevention, intervention, and care: 2024 report of the Lancet standing Commission. Lancet. 2024;404(10452):572-628. thelancet.com.
- NHS. Memory loss (amnesia): when to see a GP and causes. 2023. nhs.uk.
- Muangpaisan W, et al. Reversible dementias. Indian Journal of Psychiatry / NIH PMC. 2010. PMC3038529.
- Mitchell AJ, Shiri-Feshki M. Rate of progression of mild cognitive impairment to dementia in clinic- versus community-based cohorts. Acta Psychiatr Scand / NIH PMC. 2009. PMC2863139.
- Lin FR, Pike JR, Albert MS, et al. Hearing intervention versus health education control to reduce cognitive decline in older adults with hearing loss in the USA (ACHIEVE): a randomised controlled trial. Lancet. 2023;402(10404):786-797. thelancet.com.
- Young J, Angevaren M, Rusted J, Tabet N. Aerobic exercise to improve cognitive function in older people without known cognitive impairment. Cochrane Database Syst Rev. 2015;(4):CD005381. PMID 25900537.
- Ngandu T, Lehtisalo J, Solomon A, et al. A 2 year multidomain intervention of diet, exercise, cognitive training, and vascular risk monitoring versus control to prevent cognitive decline in at-risk elderly people (FINGER): a randomised controlled trial. Lancet. 2015;385(9984):2255-2263. thelancet.com.
- Alzheimer's Society. How many people have dementia in the UK? 2024. alzheimers.org.uk.
- National Institute for Health and Care Excellence. Dementia: assessment, management and support for people living with dementia and their carers. NICE guideline NG97, 2018. nice.org.uk.
This article is educational and does not constitute medical advice, diagnosis, or a treatment recommendation. Medication uses described as “off-label” are not licensed for that purpose in the UK and should only be considered under qualified clinical supervision. Always speak to your GP, pharmacist, or a registered specialist before starting, stopping, or changing any treatment. If you have severe or alarm symptoms - unintentional weight loss, blood in your stool, difficulty swallowing, persistent vomiting, a fever, or severe pain - seek urgent medical care.