Amy Schumer has been diagnosed with Cushing syndrome.

Schumer appeared earlier this month on "The Tonight Show with Jimmy Fallon" during a press tour for Season 2 of Life & Beth on Hulu and received an onslaught of online criticism regarding her appearance. The comedian opened up to journalist Jessica Yellin about her health journey in the News Not Noise column on Substack.

"I was also in MRI machines four hours at a time, having my veins shut down from the amount of blood drawn and thinking I may not be around to see my son grow up. So finding out I have the kind of Cushing that will just work itself out and I'm healthy was the greatest news imaginable," Schumer said in the interview with Yellen.

Amy Schumer calls out trolls, says she'owes no explanation' for her 'puffier' face

According to Mayo Clinic, Cushing syndrome "happens when the body has too much of the hormone cortisol for a long time." Schumer said she felt "reborn" while sharing the news amid the criticism she received.

"The shaming and criticism of our ever-changing bodies is something I have dealt with and witnessed for a long time. I want so much for women to love themselves and be relentless when fighting for their own health in a system that usually doesn't believe them," Schumer told Yellin.

Amy Schumer responded to face shape critics on Instagram

The "Trainwreck" star previously called out critics in an Instagram caption earlier this month. She addressed recent comments about her face and used the opportunity to give more visibility to endometriosis, a condition in which tissue that resembles cells found in the lining of a uterus grows outside of the organ.

"Thank you so much for everyone's input about my face! I've enjoyed feedback and deliberation about my appearance as all women do for almost 20 years. And you're right it is puffier than normal right now," Schumer s in said in the caption of her Instagram post which included the promotional art for "Life & Beth" co-starring Michael Cera.

She explained that she has endometriosis, a diagnosis she has opened up about previously, and said that "there are some medical and hormonal things going on in my world right now but I’m okay."

What are the signs of Cushing syndrome?

There are many signs and symptoms of Cushing syndrome. According to Mayo Clinic, signs include weight gain in the face, a fatty hump between a person's shoulders, a rounded face, pink or purple stretch marks on the skin, acne, slow wound healing and thin, frail skin that bruises easily.

Cortisol is a hormone that helps the body respond to stress and is important for other body functions such as controlling blood pressure and blood sugar, reducing inflammation, helping the body use food for energy and helping the heart and blood vessels work correctly.

Contributing: KiMi Robinson