If 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.
A definitive diagnosis of Alzheimer’s disease can be made only through autopsy after death, by linking clinical measures with an examination of brain tissue. However, doctors have several methods and tools to help them determine fairly accurately whether a person who is having memory problems has “possible Alzheimer’s disease” (symptoms may be due to another cause), “probable Alzheimer’s disease” (no other cause for the symptoms can be found), or some other problem.
To diagnose Alzheimer’s, doctors may:
These tests may be repeated to give doctors information about how the person’s health and memory are changing over time. Tests can also help diagnose other causes of memory problems, such as mild cognitive impairment and vascular dementia.
For more information, see Understanding Memory Loss.
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:
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.
Early, accurate diagnosis is beneficial for several reasons. Beginning treatment early on in the disease process can help preserve function for some time, even though the underlying Alzheimer’s process cannot be changed.
Having an early diagnosis helps people with Alzheimer's and their families:
In addition, an early diagnosis can provide greater opportunities for people with Alzheimer’s disease to get involved in clinical trials. Clinical trials are research studies in which scientists test the safety, side effects, or effectiveness of a medication or other intervention.
To learn more about Alzheimer's disease clinical trials, see Participating in Alzheimer's Disease Clinical Trials and Studies Fact Sheet or go to the Alzheimer's Disease Clinical Trials Database.
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 body fluids—blood and cerebrospinal fluid—to look for the proteins tau and beta-amyloid which are commonly found in people with Alzheimer’s. In addition, scientists have developed sophisticated imaging systems that may help measure the earliest changes in brain function or structure to identify people in the very first stages of Alzheimer’s—well before they develop obvious signs or symptoms.
Watch a video about Alzheimer’s disease biomarkers.
For more information on the new developments in diagnostic research for Alzheimer’s disease, see the section in Alzheimer’s Disease: Unraveling the Mystery, "New Techniques Help in Diagnosing AD."
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:
The 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 »