How Do They Diagnose Dementia

Written by Ryan on Friday the 9th of November 2018.


The journey to diagnosing dementia can be a long and emotional one. In this blog, we aim to give you a greater understanding of how this process will unfold, what tests and scans you can expect, as well as the aftercare you can receive once a dementia diagnosis has been determined.

GP Visit

If you think that you or a loved one may have dementia then the first port of call is a visit to your GP. In this appointment, they will run through a number of questions and tests, including:

Your History – They will ask about the symptoms, when they started and how they are affecting day to day life. They will also look at any pre-existing conditions, such as diabetes or heart disease, as well as reviewing all medications. This is to check that there is not another reason behind the symptoms.

Mental Ability Test – A General Practitioner Assessment of Cognition (GPCOG) is most likely to be conducted which asks a series of questions such as the date, and memory recall questions. Whilst these tests cannot conclusively confirm dementia, they can highlight any memory issues which need further investigation.

Blood Tests – Your GP will arrange for a blood test to be taken. These blood tests will not diagnose dementia, but serve to eliminate any other potential illnesses that can be confused for dementia. The tests will be looking at:

  • Liver Function
  • Kidney Function
  • Thyroid Function
  • Haemoglobin A1c
  • Vitamin B12 and Folate Levels

Next Step

If your GP is unsure about dementia, then they may refer you to a specialist, such as a neurologist, elderly care physician and an old age psychiatrist (who has experience in dementia). This meeting will often take place at a memory clinic, alongside other professionals who are experts in dementia.

Further, more complex tests will probably be undertaken, alongside brain scans. These brain scans are:

MRI – MRI’s look at blood vessel damage that may occur in vascular dementia, and more detailed information about strokes or tumours. They can help to confirm a dementia diagnosis and the type of disease that is causing the dementia, as well as the damage this has caused to the brain.

CT Scan – A CT scan looks at a specific part of your brain in detail. It shows if the brain has shrunk in certain areas and whether strokes have occurred, which can often be a sign of vascular dementia. It will also look for evidence of a brain tumour, which may help explain certain dementia-related symptoms.

SPECT scan or PET scan – If the results of a MRI or CT scan are uncertain, then a SPECT or PET scan may be offered. This scan shows how the brain functions and looks at the blood flow. It can pick up areas of the brain that more or less active than others which can help determine which areas, if any, are affected by dementia.


Once a dementia diagnosis has been given then you, or your loved one, will be seen occasionally by your GP. This is to check on how you are getting on, and to monitor your medication, if you have been given any to help treat the symptoms of dementia. A care plan will also be given, which will look at the sort of care that may be needed. It will include:

  • Health conditions that need regular monitoring
  • How to ensure independence for as long as possible
  • Information about services that are on offer
  • Name of health or social care person

This care plan will be reviewed once a year.

A needs assessment may also be conducted by social services that looks to identify any needs there may be, such as help with personal care or food. If it is deemed that a carer is required, then a financial assessment will be undertaken to see how much personal money will be needed to contribute to care costs. It may also be decided that a move to a care home is required, this again will be assessed depending on needs, which will determine whether a residential care home or nursing home is appropriate.

Outside of these standard support processes, there is also other help in place for people with dementia. Admiral Nurses are experts in dementia care, who offer practical, emotional and clinical support to people living with dementia and their families. There are also several dementia charities in the UK that offer support and advice, including the Alzheimer’s Society, Dementia UK and Alzheimer’s Research UK.