Younger hand holding an elderly hand

10 Jul 2024

Understanding Dementia

Dementia is an overarching term used to describe a range of progressive neurological disorders that cause a decline in cognitive function – this means it affects how a person thinks, remembers and reasons. It's not a disease in itself, but rather a collection of symptoms that result from damage to the brain caused by different diseases.

Although it is more common in older individuals – with one in 11 people over the age of 65 having dementia in the UK – it is important to note that it is not a normal part of ageing. It's normal for your memory to be affected by stress, tiredness, certain illnesses and medicines. But if you're becoming increasingly forgetful, particularly if you're over the age of 65, it's a good idea to talk to a GP about the early signs of dementia.



The brain is made up of billions of neurons that communicate through synapses. When these neurons are damaged, communication breaks down, leading to symptoms of dementia. The cause of this damage varies depending on the type of dementia.

  • Alzheimer's disease is the most common cause of dementia and is characterised by plaques and tangles forming in the brain, which lead to cell death.
  • Vascular dementia occurs due to reduced blood flow to the brain, often following a stroke or a series of mini-strokes.
  • Dementia with Lewy Bodies (DLB) involves abnormal protein deposits – known as Lewy bodies – that disrupt brain function.
  • Frontotemporal dementia is a group of conditions caused by the degeneration of nerve cells in the frontal and temporal lobes of the brain.

There are also reversible conditions that can mimic dementia such as thyroid problems, vitamin deficiencies or depression. These can often be treated successfully.



The symptoms of dementia can vary greatly but generally start with mild forgetfulness and escalate to more severe cognitive impairments. Common symptoms include:

  • Memory loss
  • Difficulty in finding the right words or understanding what people are saying
  • Difficulty in performing previously routine tasks
  • Confusion and disorientation
  • Personality or behaviour changes
  • Apathy and withdrawal or depression
  • Loss of ability to do everyday tasks.

Symptoms can have a significant impact on a person's emotional and social life, leading to changes in relationships and social isolation. Memory loss (amnesia) can be annoying if it happens occasionally, but if it's affecting your daily life or it's worrying you, or someone you know, you should get help from a GP.



There is no single test for dementia. Diagnosis is based on medical history, physical examination, laboratory tests and the characteristic changes in thinking, day-to-day function and behaviour associated with each type. Brain scans, such as CT (computed tomography) or MRI (magnetic resonance imaging) scans, may be used to rule out other causes for symptoms.

Although there is no cure for dementia at the moment, an early diagnosis means its progress can be slowed down in some cases, so the person may be able to maintain their mental function for longer.



There's no certain way to prevent all types of dementia, as researchers are still investigating how the condition develops.

However, there's good evidence that a healthy lifestyle can help reduce your risk of developing dementia when you're older. This includes:

  • Maintaining a healthy diet and regular exercise
  • Keeping alcohol to a minimum and avoiding smoking
  • Staying mentally and socially active
  • Managing cardiovascular health to prevent strokes
  • Regular health check-ups to manage conditions such as diabetes or hypertension.

A healthy lifestyle can also help prevent cardiovascular diseases, such as stroke and heart attacks, which are themselves risk factors for Alzheimer's disease and vascular dementia (the 2 most common types of dementia).


While the journey with dementia can be difficult, with early diagnosis and appropriate support and care, many individuals can maintain a good quality of life for a number of years. Research continues to advance in the field of dementia, offering hope that one day we may be able to prevent it altogether or more effectively manage its symptoms.