Selena Gomez's battle with lupus is much more intense than fans may have expected it would be, the singer revealed in an Instagram post this morning (September 14).

Gomez, who first revealed she was diagnosed with the autoimmune condition in 2013, shared a photo to the social media site in which she disclosed that she underwent a kidney transplant earlier this year to treat the condition. And she thanked her friend, who served as donor, for the unprecedented compassion.

“I’m very aware some of my fans had noticed I was laying low for part of the summer and questioning why I wasn’t promoting my new music, which I was extremely proud of,” she wrote. “So I found out I needed to get a kidney transplant due to my Lupus and was recovering. It was what I needed to do for my overall health. I honestly look forward to sharing with you, soon my journey through these past several months as I have always wanted to do with you.”

“There aren’t words to describe how I can possibly thank my beautiful friend Francia Raisa,” she added. “She gave me the ultimate gift and sacrifice by donating her kidney to me. I am incredibly blessed. I love you so much, sis.”

And fans chimed in with unyielding support.

"You are extremely strong and powerful, my soul is with you this morning," one wrote, while another noted "What a wonderful friend you have. You have been truly blessed to receive such a worthy gift from her, she is your angel."

Selena Gomez's Hottest Stage Looks:

More From Mix 97.9 FM