On Monday the singer took part in a trend in which fans asked people to share a photo in response to a question.
Halsey was asked to post a photo of himself at his “lowest point” and shared a now deleted image to show his struggle with an eating disorder.
She later tweeted an apology.
“I feel very sorry to post a photo of myself showing my struggle with ED without enough trigger warning,” the tweet said. “I was very nervous about posting it and didn’t think it right. I had positive intentions. I would never want to hurt anyone who shares my struggle.”
He added “with that, I’m going to close the session now because this has become something I’m not emotionally prepared for now. I hope it’s okay.”
Last year, Halsey opened up about mental health and living with bipolar disorder.