Alzheimer's Disease Education and Referral Center

About Alzheimer's Disease: Diagnosis


What should I do if I'm worried about memory loss or possible Alzheimer's?

Doctor is giving a diagnosis to an elderly woman patientIf you are concerned about changes in memory and thinking or changes in senses, behavior, mood, or movement that do not seem normal in yourself or a family member (see Symptoms for more information), talk with a doctor. A doctor can administer a brief memory screening test that can help detect problems, and can also do a complete exam to find out if a physical or mental health issue is causing the problem.


How is Alzheimer’s disease diagnosed?

Doctors use  several methods and tools to help determine whether a person who is having memory problems has “possible Alzheimer’s disease” (dementia may be due to another cause), “probable Alzheimer’s disease” (no other cause for dementia be found), or some other problem.

To diagnose Alzheimer’s, doctors may:

  • Ask the person and a family member or friend questions about overall health, past medical problems, ability to carry out daily activities, and changes in behavior and personality
  • Conduct tests of memory, problem solving, attention, counting, and language
  • Carry out standard medical tests, such as blood and urine tests, to identify other possible causes of the problem
  • Perform brain scans, such as computed tomography (CT), magnetic resonance imaging (MRI), or positron emission tomography (PET), to rule out other possible causes for symptoms.

These tests may be repeated to give doctors information about how the person’s memory and other cognitive functions are changing over time. Tests can also help diagnose other causes of memory problems, such as mild cognitive impairment and vascular dementia. Alzheimer’s disease can be definitely diagnosed only after death, by linking clinical measures with an examination of brain tissue in an autopsy.

For more information, see Understanding Memory Loss.

What are options for further assessment and diagnosis?

If a primary care doctor suspects mild cognitive impairment or possible Alzheimer’s, he or she may refer you to a specialist who can provide a detailed diagnosis, or you may decide to go to a specialist for further assessment. You can find specialists through memory clinics and centers or through local organizations or referral services. Specialists include:

  • Geriatricians, who manage health care in older adults. They know how the body changes as it ages and whether symptoms indicate a serious problem.
  • Geriatric psychiatrists, who specialize in the mental and emotional problems of older adults and can assess memory and thinking problems
  • Neurologists, who specialize in abnormalities of the brain and central nervous system and can conduct and review brain scans
  • Neuropsychologists, who can conduct tests of memory and thinking

Memory clinics and centers, including Alzheimer’s Disease Research Centers, offer teams of specialists who work together to diagnose the problem. Tests often are done at the clinic or center, which can speed up diagnosis.

You may also want to get a second opinion. Diagnosis of memory and thinking problems can be challenging. Subtle signs and symptoms may be overlooked or unclear. Getting a second opinion helps confirm the diagnosis. Most doctors understand the benefit of a second opinion and  will share your records if you permit. A specialist can refer you to another doctor for a second opinion, or you may decide to find one yourself.

What are the benefits of early diagnosis?

Early, accurate diagnosis is beneficial for several reasons. Beginning treatment early in the disease process may help preserve daily functioning for some time, even though the underlying Alzheimer’s process cannot be stopped or reversed.

Having an early diagnosis helps people with Alzheimer's and their families:

  • plan for the future
  • take care of financial and legal matters
  • address potential safety issues
  • learn about living arrangements
  • develop support networks

In addition, an early diagnosis gives people greater opportunities to participate in clinical trials that are testing possible new treatments for Alzheimer’s disease or other research studies.

To learn more about Alzheimer's disease clinical trials, see

What new methods for diagnosing Alzheimer’s disease are being studied?

Scientists are exploring ways to help physicians diagnose Alzheimer’s disease earlier and more accurately. The ultimate goal is a reliable, valid, and inexpensive diagnostic test that can be used in any doctor’s office.

Some studies focus on changes in personality and mental functioning, measured through memory and recall tests, which might point to early Alzheimer’s or predict whether individuals are at higher risk of developing the disease. Other studies are examining the relationship between early damage to brain tissue and outward clinical signs.

Another very promising area of diagnostic research is the analysis of biomarkers—biological signs of disease found in brain images, cerebrospinal fluid, and blood—to detect early changes in the brains of people with MCI and in cognitively normal people who may be at greater risk for Alzheimer’s disease. Studies indicate that such early detection may be possible, but more research is needed before these techniques can be relied upon to diagnose Alzheimer’s disease in everyday medical practice. 

Watch a video about Alzheimer’s disease biomarkers:

Learn more

For information on new changes to the way Alzheimer's disease is diagnosed, see "Alzheimer's diagnostic guidelines updated for first time in decades" and related FAQs about the new diagnostic guidelines.

You can also watch a video about changes in the diagnostic guidelines:

Featured Research

The image of hands holding puzzle pieces shadowThe NIH-supported Alzheimer’s Disease Neuroimaging Initiative (ADNI) is a large study that uses MRI and PET scans to learn when and where in the brain changes occur as memory problems develop. These types of neuroimaging scans are still primarily research tools, but they may be used more commonly in the future to help physicians diagnose Alzheimer’s at very early stages. Read more about ADNI findings »