What are the symptoms of dementia?

Although many people think of dementia as a memory problem, dementia can cause difficulties with any of the functions of the brain.  These are often divided into cognitive changes and psychological changes, but there are also physical changes that take place.

Your brain is responsible for thinking, remembering, organising, communicating, planning, and reasoning.  It is also the seat of personality, and behaviour.  It affects feelings and can be the source of agitation.

If your brain isn’t functioning right, it can affect sensory perceptions.  You might “see” things that are not there, or fail to see things that are, even though your eyes are functioning perfectly well. This can affect balance, and combined with loss of control of movement, may cause difficulty in moving about, or even simple things like getting in and out of a chair.

Dementia is the term used for the cluster of symptoms when the brain, irreparably damaged by disease, fails in any of these functions.

Dementia symptoms vary depending on the underlying brain disease that is causing the dementia and the part of the brain affected.  Some causes, like vascular disease, can bring about an abrupt stepwise change or a series of changes because of a mini stroke.  That means a clot or bleeding in the brain.  Unlike a major stroke where all speech and movement (for example down one side of the body) may be lost, the vascular dementia impairments may be quite subtle at first.

Other illnesses, like Alzheimer’s disease, usually build up slowly over years, although there are aggressive forms of Alzheimer’s that cause more rapid deterioration.

Although the symptoms vary from one person to another there are a few common dementia symptoms.

  • Impairment of recent memory
  • Asking questions repetitively
  • Impairment of learning
  • Difficulty with reasoning
  • Becoming lost in familiar places or routes
  • Problems with planning and organisation
  • Difficulty finding words so communication is impaired
  • Problems handling money or other personal affairs
  • Anxiety and depression
  • Agitation
  • Hallucinations and paranoia

Although dementia is more of a risk the older a person is, it is not part of normal ageing.  There are tests for dementia that you may find online, but they are of limited value.  What is important is not how well you do in a test, but how you do compared to your previous capacity.

I told my doctor that I was having some difficulty with maths, and he laughed and told me that I’m still better than him. (Woman, age 72)

 This retired scientist was aware of how her capacity to do computation was slowing and she was making mistakes.  Her own awareness of change is extremely important.  A reduction from her previous capacity is more significant than how good she is now.   Therefore, diagnosis starts with careful questioning of the person and those people around them, to see what changes they have noticed over time.

There are many conditions other than dementia that might cause the symptoms described above.  For example, when someone is tired or depressed, or has an illness such as a urine or chest infection, it may look like dementia.  In hospital when a patient is unwell, in intensive care, or recovering from surgery they may suffer from delirium, which is a temporary condition involving fluctuating states of confusion.  One risk is that this delirium is mistaken for dementia and as a result the person is not given the treatments that would reverse the delirium.  That is why it is important to tell the clinical staff whether the patient had any of the symptoms of dementia before that hospital admission.

It is unusual for dementia symptoms to come on suddenly.  There is a risk that if dementia is wrongly diagnosed, inappropriate decisions might be made, such as a permanent move to a care home.

Some people display mild symptoms, which are not severe enough to be diagnosed as dementia. This is called MCI (Mild Cognitive Impairment). They say it is like being mentally tired all the time.  It can be brought on by stress and fatigue.  Many people with MCI do not go on to develop dementia, but it creates anxiety.

If you are worried you should talk to your GP at the earliest possible stage and get a full physical examination.  At that appointment they may be able to exclude dementia and treat some of the reversible causes of those troubling symptoms.

In later stages of dementia, further symptoms develop.  It has been said that the memory problems are the least of the concerns. Behavioural symptoms include agitation, anxiety, wandering, aggression, and depression.  People with dementia can turn night into day which is exhausting for family carers.

My dad would telephone me at three in the morning, complaining that it was dark and that he couldn’t find his car keys to go to work.  He was long retired from work and had “retired” from driving three years before after a driving test, but it was hard to help him to understand that. (Daughter of man, age 85)

There is lots of advice available about how to reduce those symptoms without resorting to sedation.

The person with dementia may eventually lose the capacity to speak.  In the later stages they might be unable to move unaided and require a wheelchair or be confined to bed towards the end of life.  Continence issues in the early stages may have been because the person could not find their way to the toilet on time or got in a muddle with their clothes.  In later stages the person may become simply unaware and unable to control those functions.

Unintended weight loss is a symptom towards the end of life.  It sometimes appears that there is a loss of interest in eating and drinking and the person requires frequent encouragement to remember to eat, and to be provided with tempting food.  Mechanical problems with eating and swallowing can develop, leaving the frail person at risk of choking, or a chest infection caused by breathing in mouth contents rather than swallowing them.

Someone who has been diagnosed with dementia at the earliest stage will have years of active life before them.  From time to time a person diagnosed with dementia lives for decades and continues to have stable symptoms for a very long time.  Those people are very unusual, and it is important to study them to find out what is different from the majority whose symptoms become more serious over a shorter timescale.

Professor June Andrews


Professor June Andrews

Professor Andrews is a dementia specialist and former adviser to the Dementia Trust. After a long career in the NHS, academia and government, June now works as a consultant to Sedaca Ltd, making life better for people affected by dementia. She is the author of Dementia the One Stop Guide.

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