According to the Atlanta-based Centers for Disease Control and Prevention, traumatic brain injury is a "serious public health problem in the United States." In 2013 alone, there were about 2.8 million visits to emergency rooms for traumatic brain injury-related conditions. Of these, nearly 50,000 people died.
TBI is typically caused by a blow or bump to the head, or a by a head injury that disrupts the brain’s normal functioning. It can range from mild to severe. About 75 percent of TBIs that occur each year are assessed as mild TBIs or concussions.
>> Related: Spit test could diagnose concussion in kids, study says
Most patients with traumatic brain injury undergo a neurological exam, followed by a CT scan.
For their research, the FDA evaluated data on 1,947 individual blood samples from adults with suspected mild TBI or concussion and reviewed the product’s performance by comparing blood test results with CT scan results.
They found the blood test was 97.5 percent as effective in detecting concussion and 99.6 perfect as effective in ruling out the injury.
The test also costs as little as one-tenth as much as a CT scan.
» RELATED: Which high school sports have the most concussions?
"A blood test that accurately, reliably and consistently detects the presence of brain proteins that appear in the blood after a brain injury is a major advance," Dr. David Dodick, a fellow of the American Academy of Neurology who specializes in sports medicine and neurology, told CNN. Dodick was not involved in the study.
One of the challenges of diagnosing concussions is that the injury’s symptoms can occur at various times. For some, they appear instantly. Others may not experience symptoms for hours or even days.
» RELATED: Football players under 12 at high risk of brain injury, study finds
Symptoms also vary from person to person. Some may experience light or noise sensitivity, or may lose balance.
"This is something that has been a long time coming," Col. Dallas Hack, who was director of the Army's Combat Casualty Care Research Program from 2008 to 2014 and is now retired, told the New York Times.
“The concept originally was that we would have something that medical personnel in the field would be able to use to assess whether somebody who had received a head injury needed a higher level of care,” Hack said.
» RELATED: Youth football called 'child abuse'
But Dodick told CNN that researchers still need to better understand when brains have fully healed from trauma and how the protein biomarkers may actually affect prognosis. Additionally, it's unclear whether or not the new test can determine subconcussive blows, hits to the head that don't always cause symptoms but do cause brain injury.
Subconcussive or repeat blows are believed to lead to the neurodegenerative disease chronic traumatic encephalopathy, or CTE. Over time, that damage may lead to personality changes, mood disorders and other behavioral issues.
"These occur much more often than actual concussions, especially in certain collision and contact sports,” Dodick told CNN.