Jesus Guerrero, whom Kylie Jenner called "a light in my life," died from Pneumocystis jirovecii pneumonia and cryptococcosis. Here's what those are.

Celebrity hairstylist Jesus Guerrero’s cause of death has been revealed nearly four months after his sudden passing at 34. Guerrero, who worked closely with celebrities like Kylie Jenner and Jennifer Lopez, died from severe pneumonia Feb. 22, according to a report from the Los Angeles County Department of Medical Examiner released Monday.