- More than 850,000 people in the UK are living with dementia, with numbers set to rise to over 1 million by 2025
- Dementia is not a normal part of ageing, but your chances to develop dementia increase as you get older
- 225,000 people will develop dementia this year. That’s one every three minutes.
- 1 in 14 people over the age of 65 have dementia, as well as 1 in 6 people
- Dementia is more common among women than men
- More than 40,000 people under 65 years old have dementia in the UK
Types of dementia
The symptoms of dementia are caused by a range of more than 100 diseases that cause a loss of nerve cells in the brain. It is also possible to develop more than one disease at the same time, in which case you’ll refer to it as ‘mixed dementia’.
Alzheimer’s, vascular dementia and mixed dementia are the most common types of dementia:
Around 95% of people with dementia will have one of these five main types:
- Alzheimer’s disease
- Vascular dementia
- Dementia with Lewy bodies
- Fronto-temporal dementia
- Mixed dementia
Read on to find out more about the most common types of dementia.
What is it?
Alzheimer’s disease is the most common cause of dementia.
It occurs when abnormal ‘plaques’ and ‘tangles’ build up inside the brain and cause nerve cells to die. The brain is made up of billions of nerve cells connected to each other. When the ‘plaques’ break these connections, the nerve cells start to die.
People with Alzheimer’s disease also have less of the ‘chemical messengers’ in the brain that make it possible for signals to travel between cells. This means that, in people living with Alzheimer’s disease, some of the messages travelling within the brain can get lost.
What are the symptoms of Alzheimer’s?
The symptoms vary from person to person - it is in fact very rare to find two people with Alzheimer’s who are experiencing the same symptoms at the same stage of the disease.
However, since Alzheimer’s is a progressive disease, in all cases symptoms will get worse with time as more parts of the brain get damaged.
The first symptoms of Alzheimer’s are characterised by memory lapses, especially regarding recent events, while memories for events that happened a long time ago are usually intact. The reason for these symptoms lies in the hippocampus, a region of our brain responsible for making new memories.
The hippocampus is a region of the brain where recent memories are formed. It helps us to find our way and to recognise places and positions.
With Alzheimer’s, two proteins (tau and amyloid) start to build in the hippocampus causing brain cells to die, before spreading to the rest of the brain. This is why the early symptoms of the disease usually include loss of recent memories and disorientation.
Alzheimer’s can have a big impact on people’s daily routines and activities. These are some examples of early-stage symptoms of Alzheimer’s:
- Forgetting how to do simple tasks
- Feeling lost and not recognising where you are
- Forgetting names, recent conversations or appointments
- Losing track of the time of day or date
Later stage symptoms of Alzheimer’s
As the disease progresses, people with Alzheimer’s will be likely to develop:
- Difficulty solving problems and making decisions
- Struggles in finding the right words and following a conversation
- Problems judging distance and seeing objects in three dimensions
- ‘Delusions’, meaning they may start to believe things that are not true
- ‘Hallucinations’: they may see things that are not there
- Sudden changes in mood and personality, including agitation and aggressive behaviours
They will also become more frail, and struggle to eat and walk by themselves, in which case they will increasingly need care and support.
What is it?
Vascular dementia is the second most common cause of dementia after Alzheimer’s. It occurs when blood vessels in the brain get damaged. A healthy brain needs a constant supply of oxygen and other nutrients travelling through blood vessels. With vascular dementia, blood vessels start to leak or get blocked, preventing blood from reaching the brain cells.
The most common types of vascular dementia are:
A stroke happens when blood supply to part of the brain is cut off. This is most often caused by a clot which blocks the supply of oxygen to the brain, causing brain cells to die. About 20% of people who have a stroke develop vascular dementia within the following six months as a consequence. Vascular dementia can also start after a number of mini-strokes (also called transient ischaemic attacks, or TIAs). Sometimes these mini-strokes are too small for a person to even notice.
Subcortical vascular dementia:
This is caused by changes to very small blood vessels in the brain, which become thicker and twisted, reducing the blood flow. This type of vascular dementia sees the damage of the white matter, the nerve fibres that carry signals around the brain.
What are the symptoms of vascular dementia?
The symptoms of vascular dementia can be similar to those of Alzheimer’s, including memory loss, problems with language and communication, and disorientation.
However, some symptoms are specific to vascular dementia, including:
- Struggles in concentrating
- Problems completing tasks that require multiple steps
- Slower thinking, with more time spent processing information
- Swift mood changes, from apathy to anxiety
- Loss of bladder control and/or weakness of one part of the body (in people with subcortical vascular dementia)
- Paralysis or visual and speech problems (in people with stroke-related vascular dementia)
The symptoms of vascular dementia will get worse over time, often including behaviours that can be considered as unusual or out of character, with the person affected becoming less and less aware of what happens around them.
Dementia with Lewy bodies
What is it?
Dementia with Lewy bodies (DLB) is the third most common type of dementia. The name comes from the German doctor who first identified the Lewy bodies, small deposits of proteins that form inside nerve cells in the brain. As they build up, these clumps disrupt the way nerve cells communicate.
Lewy bodies are also the main cause of movement problems in Parkinson’s disease.
The cerebrum plays a role in memory, attention, movement and in processing visual information. In DLB, Lewy bodies build up in the gray matter in the cerebrum, damaging the nerve cells in this area of the brain.
What are the symptoms of dementia with Lewy bodies?
DLB shares some symptoms with Parkinson’s disease and with other types of dementia (especially with Alzheimer’s), including memory loss and difficulty in thinking.
However, there are also a set of symptoms which are specific to DLB:
- Changes in attention: attention and alertness levels vary greatly during the day or day-to-day. People with DLB can often stare into space for a long time, or communicate in a disorganised way.
- Visual hallucinations: in the early stages of DLB, is common to see things that are not there. This may lead to ‘delusions’ (thinking things that are not true).
- Disturbed sleep: it’s common to fall asleep during the day, but struggling to sleep at night. Violent movement can occur as a result of vivid dreams while sleeping.
- Movement problems: stiffness, slower movement and shaking can occur, similarly to what happens with Parkinson’s disease. This can also lead to general unsteadiness, proneness to falls and faint.
Like the other types of dementia, dementia with Lewy bodies is progressive, and therefore symptoms will become more extensive with time.
What is it?
Frontotemporal dementia is relatively rare, and it is usually diagnosed at a younger age (between 45 and 65 years old) than other forms of dementia. People whose dementia is diagnosed before 65 years old are referred to as having ‘young onset dementia’.
Frontotemporal dementia affects the frontal lobe of the brain.
The frontal lobe plays a role in our behaviour and emotions and help us distinguish between good and bad actions. The left frontal lobe also controls speech, while the right one helps us recognise familiar faces and objects.
Frontotemporal dementia is caused by the death of several brain cells in the frontal lobe, which affect speech, personality, behaviour and emotions.
What are the symptoms of frontotemporal dementia?
The symptoms of frontotemporal dementia vary according to which part of the frontal lobe is affected.
These are the main three types of frontotemporal dementia:
Behavioural variant FTD: the most common type of FTD, it affects the part of the frontal lobe that regulates behaviour
Progressive non-fluent aphasia: affecting the part of the temporal lobe that controls speech
Semantic dementia: damaging the region of the frontal lobe that is responsible for the understanding of language
Symptoms of behavioural variant FTD:
- Lack of inhibitions: this might include behaving in socially inappropriate ways such as making inappropriate jokes or showing a lack of tact.
- Lack of interest: such as showing apathy or losing interest in looking after themselves.
- Lack of empathy: lose interest in other people’s feelings. This is only a result of the disease, not to be attributed to a person’s personality.
- Obsessions: people can develop new strong interests, which often are acted out as repetitive, obsessive behaviours.
- Changes in eating habits: it’s common to crave sweet, fatty foods, and to lose a sense of when to stop eating and drinking.
- Struggles with planning: unlike Alzheimer’s, FTD, in its early stages, does not cause problems with recent memory. Thinking issues are more around making decisions and organising.
Symptoms of non-fluent aphasia and semantic dementia:
- Non-fluent aphasia:
- Hesitant speech, mis-pronunciation and errors in grammar
- Difficulty to understand complex sentences
- Semantic dementia
- Speech is fluent, but people lose their vocabulary, often asking about the meaning of words, or describing the words they can’t remember
- Difficulty recognising familiar objects and people
The later stages of frontotemporal dementia will see less differences between the three variants, with people with the behavioural variant developing symptoms from the language variants and vice versa. Most people at the very last stages will lose the ability to communicate all together and may no longer recognise friends and family.
Between 10% and 20% of people with FTD will also develop a motor disorder, whose symptoms include slow movement, loss of coordination and twitching.
What is it?
Someone has ‘mixed dementia’ when they develop more than one type of dementia at the same time. The most common types of mixed dementia are:
- Alzheimer’s and vascular dementia
- Alzheimer’s and dementia with Lewy bodies
At least one in 10 people with dementia has mixed dementia, which is more common in people over 75 years old.
The symptoms vary according to which one of the two types of dementia is ‘predominant’.
Stages of dementia
As we mentioned, all types of dementia are progressive and see symptoms worsen with time. The way dementia progresses is different for every person involved and depends on many factors: from the health state of the patient, to their access to support and treatments, and even to their emotional resilience.
It can be useful to identify some main stages in order to understand how dementia evolves and to better plan for the future. However, it is generally better to focus on how to live well with dementia in the present time, than worrying about what may come next - especially considering that everyone will experience dementia in their own way.
Early stages of dementia
In most cases, by the time patients become aware of the first symptoms, the disease has been damaging the brain for years.
“In the early stages of dementia, the symptoms already impact daily activities, but people are still relatively independent, adopting small adjustments to their routine.”
Later stages of dementia
Someone in the later stages of dementia will experience aggravated symptoms, which depend on the type of dementia they have. They will also become frail and unable to look after themselves and do simple daily activities. They’ll therefore have to rely on someone else to take care of them.
You can find more information on the later stages of dementia on the Alzheimer’s Society website.
Rate of progression
It’s difficult to identify a reliable rate of progression for dementia, as this will depend on the person’s general health conditions (such as if they have a heart disease or diabetes), their age and on the type of dementia they have. People with early-onset dementia usually see a faster progression than people with Alzheimer’s disease, for example.
Research seems to show that life expectancy after a dementia diagnosis is around ten years, but that varies greatly from person to person, and it should just be used as a guidance.
Spotting the signs of dementia
Although the idea of getting a dementia diagnosis may be daunting, there are several good reasons for seeing your GP when you first start to notice symptoms.
Benefits of an early diagnosis
If you know what you are dealing with, you will be able to access the right support that will help you to take control, plan your future and live as well as possible.:
- Your symptoms might actually be indicative of something else, or just be a normal part of ageing.
- You will get the right information about your condition and will be able to learn about what you are facing.
- You will get a better understanding of the symptoms and an explanation of what is going on.
Research from the Social Care Institute for Excellence shows that an early diagnosis can help people to live independently in their own home for longer, with reduced care home and hospital admissions.
But how can you distinguish between the normal signs of ageing and the early symptoms of dementia? Check out these examples:
To find out more about what to do if you think you or a loved one are showing the signs of dementia, go to the chapter Diagnosing dementia.
Dementia risk factors
We are all at risk of developing dementia. However, some factors can increase one’s risk of developing the condition. Some risks factors, such as age and genetics, are beyond our control, but there are many others that depend on lifestyle choices and habits which we can change in order to prevent developing dementia.
Note that having any of the risk factors does not mean you will necessarily develop dementia. At the same time, avoiding risk factors only makes dementia less likely, but it doesn’t guarantee you will stay healthy.
Risk factors beyond our control
Age: after 65 years old, the risk of dementia doubles every five years.
Genetics: scientists have identified more than 20 genes that affect someone’s risk of developing dementia.
Family history: those who have a family member with dementia are more likely to develop the disease.
Ethnicity: people from some ethnic groups are more likely to develop dementia than others. For example, South Asian people are more likely to develop vascular dementia than white Europeans.
Lifestyle risk factors
Physical inactivity: being inactive has a harmful effect on heart health and the correct functioning of the brain.
Alcohol: alcohol consumption above the NHS recommended intake increases the chance of dementia.
Smoking: smoking affects the vascular system, including the blood vessels in the brain.
Diet: a diet that contains too much saturated fat, salt and sugar, and which leads to weight gain, affects the probability of developing dementia.
Medical: conditions: cardiovascular factors, such as high cholesterol, high blood pressure, obesity and type-2 diabetes, increase one’s chances of developing dementia.
These factors are all avoidable through lifestyle choices and regular health checks.
How to reduce your risk of dementia
While some factors causing dementia are out of our control, we can influence many others by simple lifestyle changes which are very beneficial to our overall health, not only to prevent dementia.
Eat healthy: a diet rich in fruit, vegetables, fish and cereals is recommended. Also reduce your alcohol intake, or give up alcoholic drinks entirely.
Keep your mind active: exercise your mind by learning a new language or skill, by reading challenging books or doing puzzles.
Quit smoking: the benefits of stopping smoking are evident, even in later life.
Exercise regularly: 30 minutes, five times a week is a good start.