Plans for "memory clinics" to spot and treat dementia are due to be unveiled by the government.
"Dementia isn't when you can't find your car keys. We all do that.
"It's when you're standing at the door with your keys in your hand and you don't know what they are there for."
But experts say the condition is the health and social care challenge of the 21st century, because the UK's ageing population means the numbers affected are set to soar.
To address the problem, the government is publishing its long-awaited dementia strategy, first planned for autumn last year, setting out ways of improving care.
WHAT IS DEMENTIA?
The idea that mental faculties can deteriorate with age has been recognised for centuries.
Some researchers even believe that Shakespeare's King Lear was a study of dementia.
Dementia is an umbrella term which describes a serious deterioration in mental functions, such as memory, language, orientation and judgement.
There are many types, but Alzheimer's disease, which accounts for two thirds of cases, is the most well-known.
It is named after the German scientist Alois Alzheimer who identified the condition over a century ago.
Alzheimer had studied a patient at the Frankfurt Asylum called Auguste Deter. He first saw her in 1901 and followed her case until her death in 1906.
She displayed short-term memory loss and disorientation and, after her death, an examination of her brain showed she had the tell-tale protein deposits of amyloid plaques and tau tangles which characterise Alzheimer's disease.
Less well known versions of the condition include vascular dementia - caused when the oxygen supply fails and brain cells die.
Lewy Body dementia occurs when small structures develop in nerve cells, causing the degeneration of brain tissue.
Fronto-temporal dementia affects personality and behaviour more than memory.
All forms of dementia are progressive: as the brain becomes increasingly damaged over time, so a person's symptoms will become worse.
HOW IT IS DIAGNOSED
The only accurate way to know a person has Alzheimer's is to analyse their brain in a post mortem after their death.
Trying to diagnose the condition when someone is alive can be difficult because so many of the signs are initially subtle, or shared with other illnesses.
Signs of confusion, agitation or forgetfulness are what usually first prompt a visit to the GP.
It can take weeks - or months if someone is in the early stages of the disease - to get a diagnosis.
This is because the patient needs to be monitored and tested over time to check it is dementia rather than another condition, such as depression or a brain tumour.
Dementia cannot be cured, although there are ways of alleviating symptoms, including psychological help, art therapy and music therapy.
But most attention is paid to the role three drugs can play.
These drugs, called acetylcholinesterase inhibitors, are better known as Aricept, Exelon and Reminyl.
A controversial ruling by the National Institute for health and Clinical Excellence (NICE) stated that these drugs should only be available when Alzheimer's has progressed to its moderate stages.
But campaigners say people in the early stages of the disease should also have access to the medications.
A draft of the strategy set out a number of measures including a public information campaign, better training for GPs and health professionals to help them diagnose people with dementia, and extending the existing network of memory clinics.
These would act as "hubs", where people could be referred if they were suspected of having dementia.
Campaigners welcome them.
Neil Hunt, chief executive of the Alzheimer's Society, said: "People with Alzheimer's have complex health and social care needs which could be catered for.
"The clinics would be somewhere for GPs to send someone, even if they are not sure of their condition."
But while campaigners welcome many aspects of the strategy, they are concerned about whether they will be funded properly.
There are fears that the economic downturn will affect how much money the government can allocate to dementia care.
Scotland set out priorities for dementia care in a paper published in December, while Wales is planning to publish its own strategy.