Alzheimer's Disease | Diagnosis & Tests


When should I see my doctor?

If you are worried that you or a loved one might have some of the warning signs of Alzheimer’s disease, talk to your family doctor right away. Getting an early diagnosis of Alzheimer’s will help you get treatment earlier and will give you time to address questions of care, finances, and legal issues with your family.

How does my doctor determine whether I have Alzheimer’s disease?

The diagnosis of Alzheimer’s disease may take some time. There is no test that can tell your doctor whether you have Alzheimer’s disease. So, to make sure your doctor has plenty of information to help determine the cause of your symptoms, he or she may:

  • Ask you questions about your current health and your medical history.
  • Ask you questions about your daily routine and any changes in your behavior.
  • Perform a mental exam to test your memory, problem-solving, attention, and language abilities.
  • Perform medical tests, such as blood or urine tests.
  • Perform brain scans to look for problems, such as stroke, that may be causing your symptoms.

Based on this information, your doctor can almost always tell whether you have dementia. Your doctor can tell whether Alzheimer’s disease is the cause of your dementia about 90% of the time. But Alzheimer’s disease can only be diagnosed with 100% accuracy after death, when the brain is examined under a microscope. The brain of a person who had Alzheimer’s disease will show very distinct changes that only happen when Alzheimer’s is the cause of dementia.


See a list of resources used in the development of this information.

Written by editorial staff

Reviewed/Updated: 08/12
Created: 04/12