The short answer
Dementia is not a single illness. It is a word for a group of symptoms - memory loss, difficulty with language, confusion about time and place, changes in mood, judgement and behaviour - caused by diseases that damage the brain. Alzheimer's disease is the most common of those diseases, but it is not the only one.
The symptoms are progressive, which means they change over time rather than arriving all at once. That progression is usually slow, measured in years rather than months, and it is rarely a straight line. Many people live well for a long time after a diagnosis, particularly when the right support is in place early.
What is actually happening in the brain
Different diseases damage different parts of the brain, which is why two people with dementia can look nothing alike. Damage to the areas that store recent memory produces the pattern most people recognise: the same question asked repeatedly, yesterday lost while 1962 stays vivid. Damage elsewhere produces very different first signs - problems with vision, with speech, with planning, or with personality and social behaviour.
This matters practically. A person whose language is affected may understand far more than they can express. A person whose visual processing is affected may not be being difficult about a step down into the garden: the pattern on the floor genuinely reads as a hole. Understanding which parts of the brain are involved changes how you respond.
Our companion guide on the types of dementia sets out the main diseases and the first signs each one tends to produce.
Signs that are worth a GP appointment
- Repeating the same question or story within a short space of time, and not recalling having asked.
- Struggling with familiar tasks: a recipe cooked for forty years, the route to the shops, operating the washing machine.
- Difficulty finding everyday words, or substituting a description for a name.
- Confusion about the day, the date, the season or where they are.
- Money trouble that is out of character: unpaid bills, unusual purchases, difficulty with change.
- Withdrawing from hobbies, church, the bowling club or company they used to seek out.
- Changes in mood or personality, including suspicion, apathy or uncharacteristic bluntness.
None of these on its own proves anything. Several of them together, over months, is a reason to see the GP. So is a sudden change over days or weeks, which is more likely to be an infection, a medication problem or delirium than dementia, and which needs medical attention promptly.
How a diagnosis works in Scotland
- 01
Start with the GP
The GP takes a history, runs blood tests to rule out treatable causes such as thyroid problems, infection or vitamin deficiency, reviews medication, and carries out a short memory and thinking assessment.
- 02
Referral to a memory clinic or older adult mental health team
More detailed cognitive testing, sometimes a brain scan. The aim is not only to confirm dementia but to identify which type, because that affects treatment and what to expect.
- 03
The diagnosis conversation
Ask for it in writing, ask which type has been diagnosed, and take someone with you. Most people remember very little of that appointment afterwards.
- 04
Post-diagnostic support
In Scotland, everyone newly diagnosed is entitled to a minimum of one year of post-diagnostic support from a named practitioner, covering understanding the illness, peer support, planning for future care and getting legal and financial affairs in order.
A diagnosis is worth pursuing even when nothing can be cured. It unlocks that support, it settles what the family is dealing with, and it makes it far easier to put a Power of Attorney in place while the person still has capacity to grant one. Leaving that too late is the single most common and most costly mistake families make.
What helps
There is no cure for the diseases that cause dementia, and any guide that suggests otherwise should be treated with suspicion. There are medicines that can help with symptoms for a period in some types, and your GP or specialist is the only person who can advise whether they are appropriate.
Beyond medication, the evidence for what improves daily life is strong and unglamorous: routine, familiar surroundings, good sleep, treated pain, hearing aids and glasses that actually work, physical activity, company, and occupation that means something to the person. Music is particularly powerful, because musical memory often survives long after other memory has faded. Our guide on music and dementia covers why.
Where to get help in Scotland
- Your GP for anything medical, including changes in symptoms, sleep, pain or behaviour.
- Alzheimer Scotland run a 24 hour freephone Dementia Helpline on 0808 808 3000, plus local services and carer groups across the country.
- Care Information Scotland for assessments, funding and care options.
- Your local authority social work team for a free care needs assessment and a separate carer's assessment, which you are entitled to as a carer in your own right.
- NHS 24 on 111 when something is urgent but not an emergency. In an emergency, call 999.