NATIONWIDE -- More than five million people in the U.S. suffer from Alzheimer's, the most common form of dementia.

Right now, there's only one conclusive test for Alzheimer's diagnosis -- a postmortem examination of a patient's brain.

But that could be changing, according to a study published in the journal proceedings of the National Academy of Sciences.

Researchers say they've created a blood test that allows them to identify Alzheimer's patients with up to 86 percent sensitivity and specificity.

Sensitivity refers to true positives identified by the test, while specificity refers to true negatives.

Currently, doctors diagnose Alzheimer's based on a variety of factors, including brain scans and in-depth mental testing.

A co-author of the study says the test could not only help with diagnoses, it could help monitor progression and allow doctors to tailor their treatment to their patients.

He also says the test could be used for post-injury diagnoses for athletes.

But you won't be able to ask your healthcare provider about it any time soon.

The test still has years of evaluation to go before it can be used by doctors.