Alastair Stewart has been praised for helping to raise awareness of the symptoms of dementia.

The 71-year-old former ITV News presenter revealed that he is living with the condition on Sunday, sharing that he started feeling "a bit discombobulated" about six or nine months ago when he had difficulties with the time and doing his shoelaces.

A scan revealed he had had a series of minor strokes and he was diagnosed with vascular dementia, which affects around 180,000 people in the UK and means damage has been caused to the blood cells.

Alzheimer's Research UK has since thanked the retired broadcaster for helping to breakdown stigmas surrounding the health condition.

"We really welcome Alastair’s ability to talk about this, and obviously to talk eloquently about the impact it’s having on his family," Susan Mitchell, head of policy at Alzheimer’s Research UK, told PA news agency.

"I think, to articulate that this does affect everyone… we need people to talk about it… we don’t want there to be a stigma about it, we want people to be supportive, we need people to come forward.

"Some people don’t even come forward for diagnosis, because they don’t want to know."

Mitchell also praised former GMTV presenter Fiona Phillips revealing her Alzheimer’s diagnosis and Thor actor Chris Hemsworth saying he has two copies of the APOE4 gene, making him more likely to develop Alzheimer’s.

Other celebrities who have opened up about their diagnosis of dementia and helped to raise awareness of the condition include Julie Goodyear, Tony Christie, Angela Rippon, and Bruce Willis.

Read more: Alastair Stewart: Former ITV News presenter reveals dementia diagnosis at age of 71 (National World, 2-min read)

What is dementia?

Dementia is a syndrome (a group of related symptoms) associated with an ongoing decline of brain function, according to the NHS. The condition can affect memory, as well as the way you speak, think, feel and behave.

There are many different types, with many different causes, and it is not a natural part of ageing.

Alzheimer's disease

Alzheimer's disease is the most common cause of dementia in the UK. It is a progressive condition, meaning symptoms develop gradually over many years, slowly becoming more severe.

The exact cause isn't yet fully understood, though factors that can potentially increase your risk include age, a family history, untreated depression and lifestyle factors associated with cardiovascular disease.

The first sign is usually minor memory problems, such as forgetting about recent conversations or events, or forgetting the names of places and objects.

As the condition develops and symptoms become more severe, as listed by the NHS, these include:

• confusion, disorientation and getting lost in familiar places

• difficulty planning or making decisions

• problems with speech and language

• problems moving around without assistance or performing self-care tasks

• personality changes, such as becoming aggressive, demanding and suspicious of others

• hallucinations and delusions

• low mood or anxiety

Vascular dementia

Vascular dementia is a common type of the syndrome, caused by reduced blood flow to the brain, which often gets worse over time – though it's sometimes possible to slow it down. It can either start suddenly or begin slowly over time.

Symptoms listed by the NHS include:

• slowness of thought

• difficulty with planning and understanding

• problems with concentration

• changes to your mood, personality or behaviour

• feeling disoriented and confused

• difficulty walking and keeping balance

• dymptoms of Alzheimer's disease, such as problems with memory and language (many people with vascular dementia also have Alzheimer's disease)

This can make daily life increasingly hard for someone with the condition, eventually preventing them from being able to look after themselves.

Dementia with Lewy bodies (DLB)

DLB, also known as Lewy body dementia, is another common type of dementia. It is caused by the Lewy bodies, which are clumps of protein that appear in the nerve cells of the brain. As it shares symptoms with Alzheimer's disease and Parkinson's disease, it is often wrongly diagnosed.

Symptoms listed by the NHS include:

• hallucinations

• problems with understanding, thinking, memory and judgement – this is similar to Alzheimer's disease, although memory may be less affected in people with dementia with Lewy bodies

• confusion or sleepiness – this can change over minutes or hours

• slow movement, stiff limbs and tremors (uncontrollable shaking)

• disturbed sleep, often with violent movements and shouting out

• fainting spells, unsteadiness and falls

Frontotemporal dementia

Generally speaking, frontotemporal dementia is an uncommon type of dementia. While dementia generally mostly affects people over 65, this type typically starts at a younger age. Most cases are diagnosed in people aged 45-65, though it can also present in younger or older people.

Frontotemporal dementia affects the front and sides of the brain, and causes problems with behaviour and language. Similar to other types of dementia, it usually develops slowly and gets gradually worse over a long period of time.

Symptoms listed by the NHS include:

• personality and behaviour changes – acting inappropriately or impulsively, appearing selfish or unsympathetic, neglecting personal hygiene, overeating, or loss of motivation

• language problems – speaking slowly, struggling to make the right sounds when saying a word, getting words in the wrong order, or using words incorrectly

• problems with mental abilities – getting distracted easily, struggling with planning and organisation

• memory problems – these only tend to occur later on, unlike more common forms of dementia, such as Alzheimer's disease

As well as mental symptoms, there may be physical ones too, such as slow or stiff movements, loss of bladder or bowel control, muscle weakness or difficulty swallowing. Frontotemporal dementia can also lead to someone being unable to care for themselves.

Young-onset dementia

Young- or early-onset dementia is defined as someone who develops the condition before the age of 65.

Younger people with dementia may also experience a wide range of symptoms, with the overall condition caused by a range of different diseases. However, the support they need might vary, because it might affect them in different ways.

As listed by Alzheimer's Society, these include:

• a wider range of diseases cause young-onset dementia

• a younger person is much more likely to have a rarer form of dementia

• younger people with dementia are less likely to have memory loss as one of their first symptoms.

• young-onset dementia is more likely to cause problems with movement, walking, co-ordination or balance.

• young-onset dementia is more likely to be inherited (passed on through genes) – this affects up to 10% of younger people with dementia.

• many younger people with dementia don’t have any other serious or long-term health conditions.

Younger people living with dementia may also have concerns about how it will affect their family, relationships, finances, daily life, or the risk to future children.

Help with dementia

It's normal for memory to be affected by stress, tiredness, certain illnesses and medicine, but if you're becoming increasingly forgetful (or are experiencing other signs of dementia), particularly if you're over the age of 65, it's important to talk to a GP about it.

To distinguish normal memory loss from memory loss that could be a cause for concern, question whether it's affecting your daily life. If it's worrying you, or someone you know, don't delay in seeking advice.

You can also:

• Contact Alzheimer’s Society for support and information by visiting alzheimers.org.uk/memoryloss or calling 0333 150 3456

• Use Alzheimer's Society's possible symptoms checklist to help with a medical appointment

Dementia: Read more

• What is frontotemporal dementia? Bruce Willis’ daughter discusses her father’s condition – Evening Standard, 5-min read

• Chris Hemsworth reveals how increased Alzheimer’s risk has changed his outlook on life – Men's Health, 2-min read

• Dementia could be prevented by regular hearing tests in your 30s, experts advise – Yahoo Life UK, 5-min read

Additional reporting SWNS and PA.

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