Understanding dementia blood tests
Blood tests are a key part of the diagnostic process with suspected dementia, helping to identify other potential conditions with similar symptoms.
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Blood tests for dementia
Whether for yourself or a loved one, investigating suspected dementia can be a worrying time, and it helps to have clear, straightforward information about the diagnostic process. In the UK, there are many organisations with helpful knowledge for families currently seeking a dementia diagnosis, so if you need further advice, the below list of resources could provide additional support:
- The NHS has useful information on dementia diagnosis and how blood tests work
- The Alzheimer’s Society shares how dementia is diagnosed, types of tests and scans that might be done, and how to live well after diagnosis
- Dementia UK explains in detail how to get tested for dementia
- If you are diagnosed with dementia, your local council can offer a Care Needs Assessment to find an experienced carer who can help
Professional home care services can provide specialist dementia care at home where you may be most comfortable
How do blood tests help diagnose dementia?
Certain blood tests can now help identify conditions like Alzheimer’s disease in the early stages, and ongoing research highlights how changes in blood markers like tau and beta-amyloid could indicate dementia. However, as yet these tests are not used in the NHS diagnostic process.
While blood tests in the UK cannot conclusively diagnose dementia, they can rule out treatable conditions that could mimic its symptoms and affect cognition. For example, thyroid disorders can cause mood changes and fatigue, and a urinary tract infection (UTI) can cause behavioural changes in older people.
Blood tests are typically given alongside things like cognitive assessments and brain imaging, and the combined results start to construct a clearer picture of what may be going on in the body.
What are the most common blood tests done to confirm or rule out dementia?
| Test | Why it’s done |
|---|---|
| Thyroid function | Issues like hypothyroidism can cause symptoms like difficulty concentrating |
| Blood sugar (HbA1c levels) | High/low blood sugar can cause confusion, and uncontrolled type 2 diabetes can increase dementia risk |
| Cholesterol (lipid panels) | High cholesterol can increase the risk of stroke, which can also increase the risk of vascular dementia |
| Vitamin B12 and folate levels | Nutritional deficiencies can mimic dementia symptoms like memory loss and confusion |
| Kidney and liver function | If the kidneys or liver are functioning incorrectly, toxins can build in the body and lead to disorientation, so this test evaluates creatinine/urea in the kidneys and ALT/AST/bilirubin in the liver |
How can older adults prepare for a dementia blood test?
Your doctor will give you specific instructions before attending your blood test, but you may be asked to:
- Fast for several hours before the test
- Bring a list of your current medications/supplements
- Have a family member/caregiver provide transport to reduce travel stress
- Have a family member join in the appointment for reassurance and note-taking
Blood test results look for abnormalities that could explain certain cognitive symptoms, so if the results suggest another condition–such as thyroid disease or an infection–then your doctor will begin by treating this to hopefully minimise or eliminate symptoms. If needed, follow-up tests like cognitive testing or brain imaging (MRI or CT scan) might be ordered to learn more.
What happens after a dementia blood test?
After the blood test, your doctor will let you know when results will be ready, and potentially book in a follow-up appointment to discuss them. This does not always mean they suspect you have dementia – they may wish to talk about another treatable condition. Waiting for results can be difficult, so if you have concerns or questions, don’t be afraid to share them with your GP. They may be able to put your mind at ease while you wait.
Try to surround yourself with loved ones during this time, and if you feel comfortable doing so, open up to those you are closest to. They may be able to offer advice and helpful distraction. Whatever happens, treatment and care options exist that can help to maintain your current quality of life for as long as possible.
How can home care offer support throughout a dementia diagnosis?
A professional caregiver can support you with memory loss issues and other symptoms, relieving some of the daily stress while you work through the diagnosis process. Either visiting home care or live-in home care can help by:
- Assisting with pre-appointment preparation and transport
- Observing any changes in symptoms or behaviour, and reporting concerns to the GP
- Helping with medication management for any newly prescribed treatments
- Assisting with daily activities like personal care or housekeeping if needed
- Advocating at appointments to ensure you have all of the information you need
- Supporting your overall wellbeing and mental health through reassurance
- Providing specialist dementia care if needed
How can Home Instead help you with dementia care?
At Home Instead, our Care Professionals use a dementia care programme that is City & Guilds Assured, paying great attention to match clients with a caregiver who understands the diagnosis journey they are on and how they may be feeling. We always aim to pair clients with a caregiver who will complement their personality and interests, and who has experience with their specific care needs.
As the world’s largest global domiciliary care network, we support over 100,000 older adults with personalised, tailored care at home. We believe arranging care for yourself or your loved one shouldn’t be stressful, so whatever questions you would like answered, feel free to reach out to the Home Instead team to discuss your needs.
