Signs & Types of Dementia

There are different types of dementia which affect people differently, and which can also be impacted by factors such as their environment and how others interact with them; all of which are very important. 

A person with dementia will have difficulties with thinking and memory (cognitive problems) and will often also have problems with:

  • Changes in mood, they might be nervous or anxious,
  • Difficulty recalling events that happened recently,
  • Concentrating, planning or organising
  • Making decisions, solving problems or carrying out tasks in order 
  • Following a conversation or finding the right word for something,
  • Perception, judging distances or seeing things differently 
  • Orientation – for example, losing track of the day or date, or becoming confused about where they are.

Mild Cognitive Impairment (MCI)

Mild cognitive impairment (MCI) is a condition in which someone has minor problems with cognition – their mental abilities such as memory or thinking. In MCI these difficulties are worse than would normally be expected for a healthy person of their age. However, the symptoms are not severe enough to interfere significantly with daily life, and so are not defined as dementia.

A person with MCI has mild problems with one or more of the following:

  • Memory – for example, forgetting recent events or repeating the same question
  • Reasoning, planning or problem-solving – for example, struggling with thinking things through
  • Attention – for example, being very easily distracted
    language – for example, taking much longer than usual to find the right word for something
  • Visual depth perception – for example, struggling to interpret an object in three dimensions, judge distances or navigate stairs.


It is estimated that between 5 and 20% of people aged over 65 have MCI. It is not a type of dementia, but a person with MCI is more likely to go on to develop dementia. 

Different Types of Dementia

There are many different types of dementia depending on what part of the brain is affected or damaged. Some people might be diagnosed with more than one type. The main types are: 

Alzheimer's Disease

Alzheimer’s Disease if the most common cause of dementia making up approximately 65% of all diagnoses. The exact cause of Alzheimer’s disease is not yet fully understood, although a number of things are thought to increase your risk of developing the condition.  These include:

  • Increasing age
  • A family history of the condition
  • Untreated depression, although depression can also be one of the symptoms of Alzheimer’s disease
  • Lifestyle factors and conditions associated with cardiovascular disease


Alzheimer’s disease is a progressive condition, which means the symptoms develop gradually over many years and eventually become more severe. It affects multiple brain functions. The first sign of Alzheimer’s disease is usually minor memory problems.

  • As the condition develops, memory problems become more severe and further symptoms can develop, such as:
    Confusion, disorientation and getting lost in familiar places 
  • Difficulty planning or making decisions
  • Problems with speech and language
  • Problems moving around without assistance or performing self-care tasks
  • Personality changes, such as becoming aggressive, demanding and suspicious of others
  • Hallucinations (seeing or hearing things that are not there) and delusions (believing things that are untrue)
  • Low mood or anxiety


Alzheimer’s disease is most common in people over the age of 65 although approx. 1 in every 20 cases of Alzheimer’s disease affects people aged 40 to 65. This is called early- or young-onset Alzheimer’s disease.

Vascular Dementia

Up to 20% of dementia cases have a vascular cause. Vascular dementia is the second most common cause of dementia. It is caused by reduced blood flow to the brain.

Vascular dementia can start suddenly or begin slowly over time.

Symptoms include:

  • Slowness of thought
  • Difficulty with planning and understanding
  • Problems with concentration
  • Changes to your mood, personality or behaviour
  • Feeling disoriented and confused
  • Difficulty walking and keeping balance
  • Symptoms of Alzheimer’s disease, such as problems with memory and language (many people with vascular dementia also have Alzheimer’s disease)

These problems can make daily activities increasingly difficult and someone with the condition may eventually be unable to look after themselves.

Other Types of Dementia

As already mentioned there are many different forms of dementia. These include:

  • Lewy Bodies Dementia
  • Frontotemporal Dementia
  • Mixed Dementia
  • Young Onset Dementia

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