On the last day of 2017, Tripp Halstead's mother Stacy says her son has been hospitalized yet again, and doctors aren't sure the reason why. It follows a recent hospitalization earlier this month for pneumonia.

According to posts on the Tripp Halstead Updates Facebook page, family brought him to Athens Regional Hospital because of what they thought was aspiration pneumonia. Doctors ran tests for the Flu and RSV, but they came back negative.

"He looks good this morning," Stacy wrote. "Numbers are perfect, and that's all I know."

In a follow-up post, Stacy wrote that Tripp does not have a fever, is not throwing up, and doctors don't believe he has a cold. Doctors will be running more tests to hopefully "give us some kind of answer."

"Then we can go from there with changing the tube to a GJ or ban surgery if needed," she concluded.

It's been nearly five years since the accident changed the lives of the Halstead family. Tripp had been playing outside when a large branch broke from a tree and landed directly on his head, knocking him unconscious.

Since then, Tripp's mother Stacy has been regularly updating the more than 1 million followers on her Facebook page, offering snapshots of her family and son's life after the accident.

RELATED | 5 years after life-changing accident, Tripp Halstead 'doing awesome'

PHOTOS | Tripp Halstead