There's a new blood test for Alzheimer's. Here's everything you need to know about it.

An illustration of nerve cells with plaques around them.

The U.S. Food and Drug Administration (FDA) recently cleared a blood test that detects signs of Alzheimer's disease in the brain, according to multiple studies. This is the first-ever blood test available for this common form of dementia.

Here's how the new blood test works and why it could be useful to patients.