Selena Gomez recently received a kidney transplant from television actress Francia Raisa due to her struggle with lupus, the actress-singer revealed Thursday.

Gomez disclosed in an Instagram post confirmed by her publicist that she has been somewhat out of the spotlight this summer because she was recovering from the procedure. The 25-year-old calls the transplant "what I needed to do for my overall health."

The post didn't reveal Gomez's current condition or say where or when the procedure took place. Gomez's publicist declined to release more information.

Gomez wrote "there aren't words to describe" how she can thank Raisa, who she says gave "the ultimate gift and sacrifice by donating her kidney."

"I am incredibly blessed," she added.

Lupus is an autoimmune disease, where the body mistakenly attacks its own tissues, sometimes including the kidneys. One healthy kidney is all the body needs, so a single kidney transplant can resolve the problem, said Dr. David Klassen, chief medical officer for the United Network for Organ Sharing, which runs the nation's transplant system.

"Lupus tends to be a disease of younger women, and younger people tend to do better with transplants than older patients, so the expectation is she would do quite well," he said of Gomez.

Lupus also tends not to come back after the operation.