How is Alzheimer’s disease diagnosed?

Diagnosing Alzheimer’s disease can be tricky, but it’s essential to providing the best care for your loved one1

Making a diagnosis of Alzheimer’s disease can be difficult, particularly in the early stages of the disease. There is no single test that can accurately diagnose Alzheimer's disease. However, there are many tests that doctors can choose to use along with their clinical judgment. Diagnostic tests may include the following:

  • Complete medical history
    • An older couple represent the complexity of diagnosing Alzheimer's disease
      Family medical history, including the existence of Alzheimer’s disease or dementia-related disorders in family members
    • Detailed medical history, including a complete list of medications
    • Review of symptoms, including when they began, how often they are experienced, and whether they are getting worse
  • Mental status tests
    • There are a number of mental status tests that doctors may choose to use (for example, the Mini-Mental State Exam [MMSE], Mini-Cog Test, or Clock Drawing Test). These tests involve questions that determine an individual’s everyday mental skills and memory
  • Physical exam
    • Doctors will want to check overall physical health and may test reflexes, muscle tone, strength, movement, sight, hearing, coordination, and balance
    • They may also want to do some blood tests to rule out other causes of memory loss
  • Brain scans
    • To help make the most accurate diagnosis, doctors may also want to perform brain scans, such as magnetic resonance imaging (MRI) and computed tomography (CT). These scans help doctors to look at the size, shape, and position of brain tissue and can help rule out other causes of memory loss, such as stroke, brain injury, or a build-up of fluid
    • Positron emission tomography (PET) and functional MRI (fMRI) are two other types of scans that show doctors how well the brain uses glucose (a type of sugar) and oxygen – both of which can be affected in people with Alzheimer’s disease
Early diagnosis helps give people with Alzheimer’s the best chance of benefiting from therapy.