The only definite way to diagnose AD is with an autopsy, which is an examination of the body done after a person dies. However, doctors can determine fairly accurately whether a person who is having memory problems has possible AD (the symptoms may be due to another cause) or probable AD (no other cause for the symptoms can be found). To diagnose AD, doctors:
- Ask questions about a person’s 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 skills
- Carry out medical tests, such as tests of blood, urine, or spinal fluid
- Perform brain scans, such as a computed tomography (CT) scan or magnetic resonance imaging (MRI) test
These tests may be repeated to give doctors information about how the person’s memory is changing over time. Sometimes these tests help doctors find other possible causes of the person’s symptoms. For example, thyroid problems, drug reactions, depression, brain tumors, and blood-vessel disease in the brain can cause AD-like symptoms. Some of these other conditions can be treated successfully.
Why is early diagnosis important?
Early diagnosis is beneficial for several reasons. Having an early diagnosis and starting treatment in the early stages of AD can help preserve function for months to years, even though the underlying AD process cannot be changed.
Having an early diagnosis also helps patients and their families:
- Plan for the future
- Make living arrangements
- Take care of financial and legal matters
- Develop support networks
Finally, an early diagnosis can provide greater opportunity for people with AD 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.