Aaron Carter is fighting back against a "so-called fan" who he overheard body-shaming him.
The 29-year-old singer took to Twitter on Thursday to open up about the experience, explaining that his appearance is a result of medical issues and an "eating disorder."
EXCLUSIVE: Aaron Carter Opens Up About His Sobriety: 'The Misconceptions Are That I'm a Meth Head'
"I'm entirely hurt by a so-called fan that I just encountered. She wasn't realizing I was listening, she said I look like I have cancer. This is body shaming. You guys are bullying me. I've already addressed my medical issues," Carter tweeted. "I've literally had the hardest week of my life, my dad past [sic] away, my late sister's birthday anniversary was June 6th & people #BodyShame me."
WATCH: Aaron Carter Posts 'Heartbroken' Message and Photo, Denies Having a 'Mental Breakdown'
Hours later, Carter revealed that he was headed to the emergency room "to get a little check up."
"Lots of shows lately, had to head up to ER just to get a little check up. These shows are crazy lately, gotta make sure I stay strong," he wrote, before sharing pics from his hospital visit. "Been in the hospital three times this month, dealing with health issues and broken fingers, as well as things I can't legally discuss."
RELATED: Aaron Carter Goes on Twitter Rant About His Weight: 'I've Been Very Stressed'
"That's why people cal me a meth head. And a heroine addict," he explained to one fan who commented saying they weren't aware of his eating disorder. "I promise I'll work on getting bigger physically. I have medical issues I don't want to discuss at this time. #GodBless."
WATCH: Aaron Carter Reveals What Sets Him Apart From Justin Bieber, Tells Pop Star to ‘Open Your Eyes’
Carter spoke more about the condition that makes him "skinny" on Twitter last month, revealing that his weight is caused by a hiatal hernia that he was diagnosed with at age 19.
"I didn't choose that. Be kind to me," he wrote at the time. "It's a terrible stress condition that affects me having an appetite and I'm sorry this is the way I am. Basically I have an eating disorder."
See more in the video below.