Diagnostic Tests

There are no laboratory tests to confirm Alzheimer's disease. Your doctor will assume a diagnosis of Alzheimer's after a thorough clinical evaluation and a series of tests. Your doctor will also use these tests to eliminate the possibility of other conditions causing the dementia.

At first your doctor will ask about your symptoms and medical history. A physical exam will be done. Your doctor may also order some of the following tests:

Your doctor may perform these tests to determine if you have signs of dementia, how severe the dementia is, or to look for other causes of dementia. These tests may include:

Additionally, electroencephalogram (EEG) is a test that evaluates and follows the electrical activity of the brain. It is not a common test for evaluating most dementias but it may be done.

Blood and urine tests may be ordered to look for other conditions that cause dementia. The tests may include:

Genetic tests can look for markers that increase your risk for early-onset Alzheimer’s. Your doctor may recommend this test if you have family members with this condition.

An Alzheimer’s disease diagnosis usually falls into one of three categories:

  • Probable Alzheimer’s disease—This indicates that other dementia-related disorders have likely been ruled out. The symptoms are most likely due to Alzheimer’s disease. At least two areas of cognition are affected. One area is a worsening of memory.
  • Possible Alzheimer’s disease—The dementia is possibly caused by Alzheimer’s disease. There may be other disorders that are causing of the dementia.
  • Definite Alzheimer’s disease—This diagnosis can only be made at the time of death. It is done through an autopsy when the brain tissue can be examined. This is the only way to diagnose the disease with complete certainty.