What is dementia?

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Dementia is an umbrella term for a range of progressive conditions that affect the brain. There are over 200 subtypes of dementia, but the five most common are: Alzheimer’s disease, vascular dementia, dementia with Lewy bodies, frontotemporal dementia and mixed dementia.

The brain is made up of nerve cells (neurones) that communicate with each other by sending messages. Dementia damages the nerve cells in the brain so messages can’t be sent from and to the brain effectively, which prevents the body from functioning normally.

Regardless of which type of dementia is diagnosed and what part of the brain is affected, each person will experience dementia in their own unique way.

Dementia can affect a person at any age but it is more commonly diagnosed in people over the age of 65 years. A person developing dementia before age 65 is said to have young onset dementia.

There are over 850,000 people living with dementia in the UK and this is set to rise to over one million by 2025.

Symptoms of dementia

Regardless of which type of dementia is diagnosed and what part of the brain is affected, each person will experience dementia in their own unique way.

The symptoms of dementia can include:

Memory problems

People with dementia might have problems retaining new information. They might get lost in previously familiar places and may struggle with names. Relatives might notice the person seems increasingly forgetful, misplacing things regularly.

Cognitive ability, i.e. processing information

People with dementia may have difficulty with time and place, for example, getting up in the middle of the night to go to work, even though they’re retired. Also their concentration could be affected. There may be a difficulty when shopping with choosing the items and then paying for them. For some people the ability to reason and make decisions may also be affected. Some may get a sense of restlessness and prefer to keep moving than sit still; others may be reluctant to take part in activities they used to enjoy.


People with dementia may repeat themselves often or have difficulty finding the right words. Reading and writing might become challenging.

They might experience changes in personality and behaviour, mood swings, anxiety and depression. They can lose interest in seeing others socially. Following and engaging in conversation can be difficult and tiring, and so a formerly outgoing person might become quieter and more introverted. Their self-confidence might also be affected.

Types of dementia

These are the most common types of dementia:

Alzheimer’s disease

Alzheimer’s disease is the most common type of dementia in the UK. It is a physical condition caused by changes in the structure of the brain. This is due to a build-up of proteins, resulting in ‘plaques’ and ‘tangles’ which damage the brain cells’ ability to transmit messages and eventually lead to brain cell death. Signs of Alzheimer’s tend to develop gradually over time and can affect concentration, memory, communication and word finding and skills such as reading, writing, numeracy, planning and sense of direction.

Medication is available which may help to slow progression but it does not prevent or cure Alzheimer’s disease.

Vascular dementia

Vascular dementia is the second most common type of dementia. It is caused by problems in the supply of blood to the brain cells, commonly due to strokes or a series of small strokes, known as Transient Ischaemic Attacks (TIAs), which cause areas of localised cell damage in the brain.

Changes in a person’s condition as a result of TIAs or a larger stroke are often sudden, before their condition plateaus. But the damage caused often means the person does not function in quite the same way as they did before.

Frontotemporal dementia

Frontotemporal dementia is a progressive condition which means that the symptoms worsen over time. This tends to affect people aged 45 to 65 years but people can be older in age. The areas of the brain most affected are the:

  • frontal lobes which are important for personality, social functioning, decision making, problem solving, insight, empathy, motivation and planning. Dementia that predominantly affects the frontal lobes can be called frontal dementia, behavioural variant frontotemporal dementia or Pick’s disease
  • temporal lobes which are important for speech, word finding, comprehension and language ability. The hippocampus (important for memory formation) is also located in the temporal lobe. Dementia that predominantly affects the temporal lobes can be called semantic dementia or primary progressive aphasia

Often frontotemporal dementias are not recognised and diagnosed until the person has had signs and symptoms for four to five years as the early signs are often missed or misattributed by the person, their family and health professionals

Dementia with Lewy bodies

Dementia with Lewy bodies is a progressive condition which means that the symptoms worsen over time. It affects movement and motor control.

A person with dementia with Lewy bodies might:

  • be prone to falls
  • have tremors (similar to Parkinson’s disease)
  • have trouble swallowing
  • shuffle when they walk
  • experience disrupted sleep patterns due to intense dreams/nightmares
  • have visual and auditory hallucinations due to the nerve cell damage.

Memory is often less affected than with other types of dementia, but a person might experience sudden bouts of confusion which can change on an hourly basis.

How to get a diagnosis of dementia

If someone is showing symptoms associated with dementia it is important to visit a GP as soon as possible. Some conditions might look like dementia as they affect a person’s memory, concentration or behaviour but are treatable if addressed quickly. These include: infections, thyroid problems, delirium, confusion, vascular problems related to circulatory issues, vitamin B12 deficiency, sleep apnoea, stress, anxiety and depression.

To establish if dementia is present, a GP will take a medical and family history of the person, and will screen them for mental health and cognitive issues by: asking questions, testing concentration, short term memory, mood and behaviour changes.

The GP may then request blood tests, an MRI or CT scan to examine the structure of the brain, or request a chest X-ray to check for any chest conditions.

They may also refer the person to a memory service/clinic, or to a specialist for further investigation and assessment.

If a diagnosis of dementia is given, the GP should then ensure that the person with the diagnosis and their family are made aware of any specialist advice and support services in their area, as well as referring them for further assessments and treatments that may help. This support can come from a range of organisations, including health and social care professionals, charities, and the voluntary sector.

You can call or email our Admiral Nurses for specialist support and advice. Call 0800 888 6678 or email helpline@dementiauk.org.

Who gets dementia and can it be prevented?

About 10% of young onset dementias can be due to genetic mutations such as some forms of frontotemporal dementia, Huntington’s disease and rare varieties of Alzheimer’s disease.

However, in older age most cases of dementia are not thought to be inherited and recent research suggests that you can delay or prevent dementia by making some modifications to your lifestyle. Everything that keeps your heart healthy, can also keep your brain healthy. So, eat a balanced healthy diet, keep hydrated, don’t smoke, avoid drinking too much alcohol, have regular check-ups with your GP and keep your cholesterol and blood pressure under control. If you have been diagnosed with type two diabetes you will need to follow any advice you have been given to manage this effectively and ensure that your blood sugar levels remain under control.

Stay physically active and mentally stimulated with different activities so that you use different parts of the brain. For example, walking, gardening, singing, art, music, reading, and other hobbies and interests are thought to help.

There is no compelling research that says doing puzzles will improve brain health, however, learning another language is helpful because different parts of the brain are stimulated and this can enhance cognitive function.

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