Kyle Busch's death explained by severe pneumonia, sepsis

Kyle Busch, the 41‑year‑old two‑time NASCAR Cup Series champion, died after severe pneumonia spread to sepsis, a rapid progression highlighted by his recent racing activity and emergency‑room symptoms.

On Saturday, the family of NASCAR legend Kyle Busch released a statement that unveiled the cause of death of the two-time Cup Series champion, who passed away on Thursday at the age of 41.

"The medical evaluation provided to the Busch Family concluded that severe pneumonia progressed into sepsis, resulting in rapid and overwhelming associated complications," the Busch family statement read. "The Family asks for continued understanding and privacy during this difficult time."

Most people have had pneumonia or know someone who has. It’s common enough that it can feel routine; something you treat, something you recover from, something you push through. 

Sometimes it isn’t.  

Double pneumonia means both lungs are infected at once, according to the Cleveland Clinic. It sounds worse than a single-lung infection, and sometimes it is. Not always, though. A person can have a relatively mild case in both lungs or a catastrophic one. The name alone doesn’t tell you how sick someone is.