The six early warning signs of dementia that EVERYONE needs to know: Read over expert guide to diagnosing the disease - with the latest science and expert advice

Dementia is now the UK's biggest killer. More than a million people are thought to have the condition, according to a report for the charity Alzheimer's Society published last year.

Yet it's estimated that a third of those currently struggling with dementia are undiagnosed.

'This is largely because many people assume symptoms such as memory loss and confusion are a natural part of ageing and that there's nothing that can be done, so they don't see their GPs for help,' says Professor Dame Louise Robinson, regius professor of ageing at Newcastle University and a practising GP.

Another major obstacle is a lack of awareness of early symptoms. Although memory loss is the best-known, it's by no means the only sign of dementia –and isn't present in the early stages of some types such as frontotemporal dementia (FTD).

'In all, there are actually more than 100 types of dementia, all of them affecting slightly different parts of the brain and causing different symptoms, particularly in the early stages,' explains Dr Richard Oakley, associate director of research and innovation at Alzheimer's Society.

Dementia is in fact an umbrella term for a collection of terminal brain diseases of which Alzheimer's disease, associated with the abnormal build-up of amyloid and tau proteins in the brain, is the most common, accounting for around 60 per cent of cases.

Other better-known types include vascular dementia, caused by reduced blood flow to the brain, often after a stroke; Lewy body dementia, linked to abnormal build-up of proteins called Lewy bodies; frontotemporal dementia, also linked to abnormal protein build-up and affecting the frontal and temporal lobes, causing language problems and changes in personality and behaviour; and Parkinson's dementia, which is linked to Parkinson's disease (although not everyone with Parkinson's develops it).

Many people also eventually develop a combination of different types of dementia – known as mixed dementia.

To help identify if you or a loved one might be at risk, Alzheimer's Society has compiled a checklist of symptoms to aid in conversations with a GP.

Visit alzheimers.org.uk/checklist or call its Dementia Support Line on 0333 150 3456 for more information.

Here, leading experts explain six of the most common early dementia symptoms to watch out for. These may occur alone, or several may be seen together.

Confusion or disorientation can be a warning sign, says Professor Dame Louise Robinson.

If this happens quickly, over a few hours or days, it's usually due to a treatable medical condition, like a chest or urine infection or the effect of certain drugs – for example very strong painkillers or sleeping tablets.

However, confusion over a longer period is common in early stages of several types of dementia, including Alzheimer's and vascular dementia, where it is caused by reduced blood flow to the brain.

'People may repeatedly turn up for an appointment on the wrong day or buy grocery items they've already bought, for instance,' says Professor Robinson. 'In such instances you should see a doctor.'

Memory loss can be a symptom of any type of dementia and is often one of the first signs of Alzheimer's disease.

It's caused by damage to parts of the brain involved in creating and retrieving memories, typically the hippocampus, part of the medial temporal lobe.

'Abnormal growth of amyloid and tau interferes with the brain's ability to process information, affecting how we store and retrieve memories,' explains Professor Robinson.

Many of our body's functions slow and weaken with age, including memory. But while forgetting where you put your spectacles from time to time may be normal, seek medical help if memory problems worsen (particularly if you are under 65) or if they are interfering with your ability to live your daily life.

'Protein builds up in the brain, which copes for a while – but this affects connections between cells which start failing.

'Brain cells then begin to die off and the brain shrinks,' says Nick Fox, professor of neurology at University College London and director of its Dementia Research Centre. See your GP if family or friends regularly express concern – even if you don't agree – as they are best-placed to observe changes, says Professor Robinson.

Dementia interferes with the brain's ability to create and store new memories, which explains why people with dementia can recall things from a long time ago but forget a conversation they've just had.

Other common experiences include forgetting the names of people and objects, getting lost in familiar surroundings, forgetting how to carry out tasks such as making a cup of tea, forgetting appointments and anniversaries and not being able to keep track of medication.

Most people struggle to find the right word from time to time as they get older – but these will usually come back after an hour or so and are momentary lapses, says consultant neurologist Paresh Malhotra, professor of clinical neurology at Imperial College London. 'However, it may be a symptom of dementia if someone is progressively finding it difficult to find the right word or understand the meaning of certain words,' he says.

Other signs include jumbling words or repeating them, or shortening sentences.

Such problems are due to damage to the areas of the brain involved in language skills, speech formation, comprehension and communication, including the frontal lobes and temporal lobes.

This might initially affect people with frontotemporal dementia but can also be common in vascular dementia, especially if areas of the brain responsible for language have been affected by reduced blood flow.

'If language is the earliest sign a loved one is developing dementia, this can be difficult to spot initially,' says Professor Malhotra. 'The person may have found other ways to get round words they can't remember, such as gesturing or saying 'thingummy'. So it may be some time before you realise that their vocabulary is actually diminishing.'

Vision is a complex process involving the information our eyes receive and our brain's interpretation of this data.

'I sometimes see people who have been told by an optician that there's nothing wrong with their sight yet they are having difficulties with their vision,' says Professor Fox, a specialist in rarer types of dementia.

'The back of the brain – the occipital and parietal lobes – are involved in processing information from our eyes and if cells and neural pathways in these areas become damaged by a build-up of amyloid and tau proteins then the first clues may be in visual problems,' he explains.

Warning signs include having problems with judging distances – such as missing steps or clipping wing mirrors – that aren't resolved by a trip to the opticians and seem to get worse. Other visual symptoms include having trouble recognising objects or being confused by complicated patterns.

These can be the only symptoms in the early stages of some rarer types of dementia – sufferers may do well in memory tests as these parts of the brain have yet to be affected.

A SHIFT in the way a loved one interacts with others, particularly if it's untypically inappropriate, can be a signal of dementia affecting the frontal lobes of the brain, says Professor Fox.

'This can be hurtful to witness, as they often also become much less empathetic to other people's feelings and say or do wounding or insensitive things,' he says.

This can be an early sign of frontotemporal dementia, one of the most common types of early-onset dementia (dementia affecting those under 65).

Other symptoms of FTD can include becoming fixated on routines (the person may often be reluctant to change their clothes, for instance) and rigid thinking – yet often their memory is still good, so these are often overlooked as potential early dementia symptoms.

Becoming anxious, sad, withdrawn or losing interest in social interactions and hobbies can also be symptoms in the early or middle stages of Alzheimer's, vascular dementia, FTD and Lewy body dementia, where it sometimes overlaps with hallucinations (seeing things or people that are not there).

'There's a natural tendency to assume that anxiety and depression, particularly in early onset dementia patients, is due to other factors such as menopause or stress at work,' says Professor Fox.

Singer-songwriter Alexis Strum, 47, from Chingford, east London, lives with her daughter, ten. Her mother Evalina, 82, a retired teacher, was diagnosed with Alzheimer's in 2021 and is now in a care home. Alexis says:

I first knew something was wrong back in 2018. Mum had driven me to an osteopath appointment. Afterwards, I was clipping my young daughter into the child seat when Mum started driving off with the door open.

'I screamed at her to stop and reverse the car, as my foot was trapped under the wheel. She turned to look at me with a totally blank expression – it was eerie.

'She eventually reversed the car, releasing my foot (luckily it was only bruised). But it was so unlike her. She didn't apologise and when I asked her why she'd done it, she said: 'I was in a hurry', as if it was my fault. I dropped the subject but it niggled.

'There were other strange incidents – she'd turn up for things on the wrong day. Once, while washing up, I noticed she put the plates to one side still dirty.

'I began researching dementia online and saying to my 79-year-old dad Steven, an accountant, that she should see a doctor.

'Dad was initially reluctant so we left it but, in December 2021, I persuaded a family friend, who's a psychiatrist, to assess Mum.

'After she failed to answer simple questions such as 'Who is the Prime Minister?' the friend diagnosed her with Alzheimer's. It was later confirmed by a memory clinic assessment and MRI scan.

'By this point, Mum's disease had moderately progressed. At first, Dad tried to care for her at home but he's not in the best of health and she became aggressive to carers.

'She is now in a local authority care home. We visit her regularly but she doesn't know who we are.

'Earlier diagnosis might have meant that her condition could have been stabilised by medications for a while and we might have had more time with her.

• Alexis's new single, Swim, is raising money for Alzheimer's Society. See justgiving.com/page/alexisstrumswim

The first 'tangible sign' that John Suchet's beloved wife had dementia came as the couple prepared to board a flight to France.

They were at the departure gate at Stansted airport when Bonnie said she was 'nipping to the loo', the veteran broadcaster recalls.

He waited and waited. The other passengers boarded, but no Bonnie.

Finally, there was a call for him on the airport tannoy.

'She was just standing there at the help desk smiling sweetly, and said: 'Oh thank goodness I've found you!' says John, whose long and distinguished career as a journalist included presenting the ITN News at Ten for 17 years.

John and Bonnie hastily took their seats on the plane – as they did so, John recalls thinking: 'Something must be going on here, but goodness knows what it is.'

The words Alzheimer's and dementia never entered his head, he now admits. But looking back, he now recognises her forgetfulness that day was one of several warning signs in the three years running up to her eventual diagnosis in 2006, aged 64, including shopping for groceries only to return with 12 pots of yoghurt.

'It's natural instinct to dismiss incidents such as these as a momentary lapse of concentration,' he says. 'After all, who hasn't forgotten a face, an email address or where they left the car keys? When you live with someone you just step in and answer for them.'

Today, he's keen to emphasise to anyone else who may find themselves in a similar situation how vitally important it is not to dismiss these kinds of hunches or doubts.

'Ask for help even when you think it's too early to,' he stresses. 'Ask if you're worried. Whether it's a spouse or someone really close to you, stop making allowances.'

Although the first port of call should be your GP, you should also insist on brain scans or further referrals if still in doubt, he says. Looking back, he wishes this is something he'd appreciated himself, not least so he'd known what he was dealing with and been able to seek help sooner.

'Getting the diagnosis is a major part of the problem, because you go on for so long without seeking help,' he says.

A lack of diagnosis also has consequences for the carer, something he's at pains to stress.

'The person with the disease is the priority. But the important thing about dementia is it's the carer who can often suffer more than the person with it.

'Very often the carer will die before the spouse. I know of cases where this has happened.'

Initially, John tried to care for Bonnie at home, with the help of Admiral Nurses (specialist dementia nurses supported and trained by the charity Dementia UK). But in 2009, he took the heartbreaking decision to move her to full-time care in a home.

To this day, he's not sure whether the 'wonderfully calm, placid, easy-going' Bonnie ever realised she had dementia.

'From the day she was diagnosed, till the day we lost her, she never mentioned the A word or the D word once,' he says.

It's ten years since Bonnie died and John is now enjoying his 'second career' as a presenter and writer on Beethoven and classical music. His latest book,

In Search Of Beethoven – A Personal Journey, is out in paperback in August.

But he still finds it deeply painful to talk about how the disease robbed him of the glamorous woman he's described as 'the love of my life', and to whom he was married for 24 years.

'It was just horrendous. They're slowly vanishing before you, slowing losing their personality.

'Time heals up to a point… then you get 'ambushes', whether it's a book, a film or a place that's mentioned and it all comes back,' he says.

The most recent 'ambush' was the tenth anniversary of Bonnie's death on April 15, 2015, a memory that John admits is still raw. 'It never goes away,' he says.

He's since remarried, to Nula, whose first husband James Black, a television director and writer, died from frontotemporal dementia, a rarer form of the disease, aged 68, in 2014.

The couple originally met as both Bonnie and James were being looked after in the same care home. 'There are still four people in this relationship because it was this that brought us together,' says John.

John and Nula, an artist and designer, are now united in campaigning to raise awareness of dementia, its toll on carers and the lack of adequate care.

Although both Bonnie and James were diagnosed around 20 years ago, John and Nula are concerned that little has changed since.

'There is a distinct lack of care,' says John, citing lack of diagnostic tools and specialised services as well as support for hard-pressed carers.

'Today, one in three of us will get dementia and recently it passed cancer as the biggest killer in the country – so why isn't there more support for carers?'

Organising and planning abilities can deteriorate when the frontal lobe of the brain responsible for these functions becomes damaged, due to injury or disease.

So if you notice a change in someone who is usually very organised, then it is worth raising concerns, says Paresh Malhotra, professor of clinical neurology at Imperial College London.

'Perhaps they always used to organise the family holiday, sorting flights, car hire and accommodation for a whole group, but now you find elements are being missed.

'Or they may have been the person responsible for doing the accounts, or another task that involves juggling a number of components, and you notice that this isn't being done as it used to be,' he says.

You may notice someone developing these symptoms in isolation or in conjunction with other symptoms, adds Professor Malhotra, who says that different combinations of symptoms can signal different types of dementia.

Problems with organising, planning and concentrating on everyday tasks can be a symptom of many forms of the condition, including Alzheimer's and vascular dementia.

'Planning and visual difficulties together can signal Lewy body dementia, especially when these vary from day to day, while planning and behavioural issues can point to temporal dementia (FTD),' adds Professor Malhotra.