Gaga tweeted her sweet message on Friday, calling Gomez a "warrior princess" and "an inspiration."
Last week, Gomez shared a heartwarming photo of herself and friend Francia Raisa smiling at each other in hospital beds. Raisa, who just went back to work on her new series Grown-ish, donated her kidney to the "Fetish" singer after her battle with lupus grew more life-threatening.
Gomez thanked her longtime friend in a lengthy Instagram post, saying: "There aren’t words to describe how I can possibly thank my beautiful friend Francia Raisa. She gave me the ultimate gift and sacrifice by donating her kidney to me. I am incredibly blessed. I love you so much sis."
It's really inspiring to see both Gaga and Gomez talk about their chronic illness, especially since their conditions are not uncommon. The CDC reports that approximately 4 million adult Americans have fibromyalgia, and the National Resource Center on Lupus claims that about 1.5 million Americans have lupus.
"My heart is with selena gomez and lady gaga today," she wrote. "We're all human & need self care. i hope both these icons heal safe & feel good. such wonderful role models for being so honest with a very critical world."