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HealthInfo Canterbury

Tests and diagnosis for dementia

There's no straightforward test for dementia. Doctors usually make a diagnosis by ruling out other medical conditions that might cause you to have memory loss. These include depression, side effects of medication, infections, vitamin deficiencies, thyroid gland problems and brain tumours.

Your doctor might examine you and ask questions about your memory-related symptoms, your family history, and your overall health and lifestyle. You might need to have a blood test and provide a urine sample for testing.

Other tests

Your doctor may suggest some special tests to look at your memory and mental ability. These don't take long and are usually a series of questions or other exercises that your doctor or practice nurse asks you to complete. Your doctor may also refer you for a brain scan. A brain scan isn't necessary to diagnose dementia, though it is useful in some circumstances.

What to do if you think a relative or friend has dementia

If you're worried that someone close to you may have dementia, encourage them to see their doctor. They may agree for you to go to the appointment with them. If you're having trouble convincing them to see a doctor, you could suggest they have a check-up. This could be for a symptom that the person acknowledges they have, such as failing eyesight or headaches. It could also be for something like a review of their medications.

On the next page: Living with dementia

Written by HealthInfo clinical advisers. Last reviewed August 2018.

Page reference: 5540

Review key: HIMLD-33325