ER doctor reveals how pneumonia can suddenly turn deadly after Kyle Busch’s death

The sudden death of Kyle Busch has drawn attention to a rare but devastating medical progression: when pneumonia escalates into fatal sepsis.

An ER doctor spoke with Fox News Digital about how sepsis can trigger a rapid health decline.

"Sepsis is actually not a specific disease or diagnosis, but rather the syndrome that occurs when the body has certain abnormal findings and a presumed infection," said Dr. Kenneth J. Perry, a South Carolina-based emergency medicine physician.

HOW PNEUMONIA PROGRESSES TO SEPSIS...