How is dementia diagnosed? The NHS pathway step by step

Dementia is diagnosed through an NHS process that starts with a GP, who checks for other causes of memory problems using a conversation, a physical examination, blood and urine tests and a memory test. If other causes are ruled out, the GP usually refers the person to a memory service or specialist, where more detailed tests and often a brain scan lead to a diagnosis.

At a glance

• The first step is a GP appointment, ideally with someone who knows the person well.
• The GP looks for treatable causes first, such as depression, infection, thyroid problems or medicine side effects.
• Specialists may be old-age psychiatrists, geriatricians or neurologists, often working in a memory clinic.
• A CT or MRI scan is commonly used; other scans and spinal fluid tests are used only when they would change the plan.
• Waiting times vary widely, from a few weeks to more than a year in total, depending on where you live.

How does the diagnosis process start?

It starts with the person seeing their GP about memory or thinking problems. If you are worried about a relative, the NHS advises encouraging them to book an appointment and offering to go too. Having someone who knows them well is useful because that person can describe changes the individual may not notice or may not remember to mention.

Before the visit, note down what has changed, when it started and how it affects daily life. Alzheimer’s Society offers a symptoms checklist, and our guide to the early signs of dementia lists common patterns. Bring a list of all medicines, including over-the-counter and herbal remedies. You can ask for a longer appointment when booking.

Many people delay. The NHS cites an Alzheimer’s Society study finding that 1 in 4 people wait 2 years before seeking help, so there is no need to wait for things to become severe.

What does the GP check?

The GP will ask about symptoms, wider health and whether the person struggles with personal care, cooking, shopping or paying bills. They will also ask about other medical conditions, family history and current medicines.

• Physical examination, which may include checks on movement, coordination, hearing and sight.
• Blood tests and sometimes a urine test, to look for causes such as thyroid problems or vitamin deficiencies.
• A memory or cognitive test, which can involve questions on memory, reasoning and awareness of time and place, and sometimes writing answers on paper.

NICE guideline NG97 says GPs should use a validated brief cognitive test (examples it names are the 6CIT, the Mini-Cog and the Test Your Memory test) and, where possible, take a history from someone who knows the person. A normal score does not rule out dementia, so the GP will weigh the result alongside everything else.

Which conditions can look like dementia?

Memory problems do not always mean dementia. The NHS lists depression, anxiety, delirium caused by an infection or another medical condition, an underactive thyroid and side effects of some medicines as possible causes. NICE also points to sensory loss and certain medicines. Our guide to delirium and urinary infections in older people explains why a sudden change should always be checked promptly.

When is a referral made, and to whom?

NICE recommends referring to a specialist diagnostic service once reversible causes have been looked into. The GP may refer to an old-age psychiatrist, a geriatrician or a neurologist, often working in a memory clinic with nurses, psychologists, occupational therapists and other professionals. NICE advises referral to a neurological service with access to specialist tests if dementia seems to be progressing unusually quickly.

If the GP does not refer, they should explain what they think is causing the symptoms and how it will be treated. Alzheimer’s Society says you can ask what makes the symptoms different from dementia, what to do if they get worse, and whether you can have a referral anyway or a second opinion. For what to expect at that appointment, see memory clinics: what to expect.

What scans and further tests are used?

NICE says further tests should be used only where they would change care, and that a normal scan does not rule out dementia. It does not recommend EEG or APOE gene testing to diagnose Alzheimer’s. The NHS states that most cases can be diagnosed after these assessments. Different types of dementia need different checks, and some people have more than one type.

How long does a dementia diagnosis take?

There is no single timescale. Alzheimer’s Society says many people are diagnosed within a few weeks, while for others it takes more than a year, and waiting for a specialist appointment can take from a few weeks to several months depending on where you live and how serious the symptoms are. NICE’s quality standard sets no fixed referral deadline. Ask the GP and the memory service what the local wait is, and ask whether pre-diagnostic counselling is available while you wait.

How is the diagnosis shared?

The NHS says a doctor should first ask whether the person wants to know the diagnosis, then explain what it may mean and leave time for questions. Unless the person decides otherwise, they and their family or carer should be told:

• the type of dementia, or that reassessment is needed;
• how it is likely to progress and what treatments are available;
• the name of a professional who coordinates their care;
• local support services, and the effects on driving or work;
• where to find financial and legal advice, with written information to take home.

Anyone who drives must tell the DVLA after a diagnosis; see dementia and driving. The GP and memory service should keep reviewing needs, and this is the moment to talk about lasting power of attorney. For emotional and practical next steps, read coping with a dementia diagnosis.

Frequently asked questions

Can a GP diagnose dementia on their own?

A GP can assess and rule out other causes, and some GPs have specialist expertise, but diagnosis is usually confirmed by a specialist service such as a memory clinic. NICE recommends specialist referral once treatable causes have been investigated.

Is there a blood test for dementia?

Routine blood tests are used to find other causes of memory problems, such as thyroid or vitamin problems, not to confirm dementia itself. NICE does not recommend gene testing to diagnose Alzheimer’s.

Do you always need a brain scan?

Not always. NICE says structural imaging (CT or MRI) is generally offered to exclude other causes, unless dementia is well established and the type is clear. Other scans are used only when they would change the care plan.

What if the person refuses to see a doctor?

Go gently and avoid forcing the issue. Suggest a general health check, offer to attend, and consider speaking to the GP beforehand. The NHS says you can encourage someone to book and offer to go with them.

Does a normal memory test mean it is not dementia?

No. NICE states that a normal score on a brief test does not rule dementia out, especially in the early stages, which is why a history from someone who knows the person matters.

Where to get help next

Alzheimer’s Society’s Dementia Support Line (0333 150 3456) can talk through the process. If a diagnosis is confirmed, our stages of dementia care needs guide explains what may come next, and dementia care at home and choosing a dementia care home cover the care options. You can also browse local services through find care.

Sources

• NHS: Getting a dementia diagnosis
• NICE: Dementia, assessment, management and support (NG97), recommendations
• NICE: Dementia quality standard, statement 2: diagnosis
• Alzheimer’s Society: How to get a dementia diagnosis
• Alzheimer’s Society: Dementia assessment with your GP
• Alzheimer’s Society: Referral to a dementia specialist

Reviewed by The Care Panel team on 9 November 2026. This guide is general information about care in England, not legal, medical or financial advice. Rules and rates change; check with your council or an adviser before making decisions.