The internet is abuzz with claims that biomarker blood tests are the key to predicting dementia 15 years out. Here's what you need to know about what these tests can — and can't — do.

Not so long ago, a blood test for Alzheimer’s disease seemed a pipe dream. Now, after years of study, the field is awash with sensitive assays that signal the proteopathic culprits Aβ and tau coalescing in the brain.

This guide provides information about blood tests for people with cognitive difficulties, such as problems with memory and/or thinking, which could be due to Alzheimer’s disease (AD). Testing for people with cognitive difficulties may be offered as part of a clinical evaluation or research study.