Halsey is in "total agony" following a series of "terrifying" surgeries to treat endometriosis.

The pop star opened up about her stint in the hospital on Instagram on Friday, January 6, where she also thanked her fans (via a hospital bed selfie) for lending her support during treatment.

"Today I braved multiple terrifying surgeries. The most important of which being the surgery that would hopefully treat my endometriosis," she wrote. "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. 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)."

"But in my recovery I am thinking of all of you and how you give me the strength and stamina to power through and prosper," Halsey continued. "If you suffer 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 and I hope so much in my heart that you can too."

See her emotional update, below:

Back in January 2016, Halsey revealed that she was suffering from endometriosis, a condition in which the internal tissue that lines the uterus grows outside of the organ, a painful disorder which can cause ovarian cysts and other fertility issues.

Look Back at Halsey's Incredible Year in 2016: