Alzheimer’s symptoms and diagnosis Find out about the symptoms of Alzheimer's and how the disease is diagnosed. Related topics: Alzheimer’s and dementia, Alzheimer’s causes and risk factors, Alzheimer’s treatment, Alzheimer’s caregiving How Biomarkers Help Diagnose Dementia Learn about biomarkers — measures of what’s happening in the body — used in dementia detection and research, including brain imaging tests such as MRI and PET. How Is Alzheimer's Disease Diagnosed? Doctors can diagnose "possible Alzheimer's dementia," "probable Alzheimer's dementia," or some other problem causing memory complaints. Learn about the benefits of early diagnosis. What Are the Signs of Alzheimer's Disease? Memory problems are typically one of the first signs of Alzheimer's disease. Learn about other common signs of mild, moderate, and severe Alzheimer's.