The 31-year-old reality star opened up about the 28-year-old sock designer in an interview with Access Hollywood. Rob Kardashian was diagnosed with diabetes after being rushed to the hospital in late December.
"He's taking it seriously," Kardashian said of her brother. "I think everything happens for a reason. If that was going to wake him up a little and take, not his life, but his health more seriously, then that's what [the hospitalization] was for."
"It was really scary," she admitted. "We were at home and he kept having trouble breathing ... We just realized that it was more serious and just hearing him breathe was really bad ... His insulin was just crazy ... Something happened where it could shut down his body."
Rob Kardashian has struggled with his weight in recent years and rarely appears in public or on social media. Kardashian encouraged her brother on Instagram prior to his hospitalization, and shared her hopes for the designer in 2016 with E! News.
"I know [it's early] but I think I've seen such a great transformation [in him] just mentally right now," the star told the website. "Again, it's only been a week, but I hope that sticks and I'm always praying and rooting for Rob. I'm very hopeful. We gotta get Rob back out there doing his thing."
Khloe Kardashian is also dealing with estranged husband Lamar Odom's health problems. The reality star said the 36-year-old former NBA player is "doing amazing" in recovery last week, and Odom was reportedly moved to a new facility over the weekend.