The "New Americana" singer, whose birth name is Ashley Frangipane, shared a photo of herself on Instagram in a hospital bed. In the photo posted Friday, Halsey gave a thumbs up to the camera while wearing a green hospital gown and blue surgical scrup cap.
"Today I braved multiple terrifying surgeries. The most important of which being the surgery that would hopefully treat my endometriosis," she began in a lengthy caption.
"For those of you who have followed this battle of mine or who may suffer with it yourself, you know the extremes to which it can be mentally exhausting and physically painful," Halsey, 22, continued. "OK HONESTLY I'm in total agony right now (and I'm going to be in excruciating pain for a while cause I had quite the cocktail of procedures today)."
Addressing her fans, the singer said that during recovery she's "thinking of all of you and how you give me the strength and stamina to power through and prosper."
Halsey also used her caption to encourage others who may be suffering from "chronic pain or a debilitating disease."
"Please know that I have found time to live a crazy, wild, rewarding life AND balance my treatment," she wrote, "and I hope so much in my heart that you can too."
The "Closer" singer concluded by letting fans know that she'll "be off the map for a few days but please know even if I'm not on social media I am thinking of you."
ABC News reached out to a rep for Halsey, but so far has not received a response.