Robert Kardashian posted a sad message on Twitter Tuesday which led to concern from his fans. The 27-year-old had deactivated his social media account months ago, but reactivated it this week.

“No one will ever understand how much it hurts,” he wrote to his nearly 5 million followers. Though he did not elaborate further, Kardashian is likely referring to his weight struggles, which are no secret at this point. His mother, Kris Jenner, has reportedly even taken him to fat camp to take part in a weight loss program. The reality star has been on a mission to lose at least 40 pounds after getting chubby once his relationship with singer Rita Ora ended last year.

On the mid-season finale of "Keeping Up With The Kardashians," earlier this month, fans saw Rob break down after opening up about his battle with the bulge. The episode revealed that Rob’s health has been declining since gaining a significant amount of weight.

“If he doesn’t change his lifestyle right away, he’s going to end up diabetic and his organs are going to shut down,” Kris told daughter Kim, in response to his blood tests results.

Kris later sat down with her son, and told him the news. “I don’t wanna see something horrible happen to you [sic]. Your liver is supposed to be between 0 and 44. It’s 217. Your liver is shutting down.”

Later in the episode, Rob expresses his insecurities, telling Kim, “I don’t really wanna film with my shirt off. … I'm sad. I don’t’ even wanna sit down because of how fat I am [sic]. I don’t know I just don’t know what to do.”