Demi, 25, has received an outpouring of support from the Hollywood community, including her ex boyfriend Wilmer Valderrama, the Jonas brothers and Ruby Rose. While Selena was not among the well wishers on social media, she did step out wearing a "keep the faith" slogan t-shirt.
"When Selena found out the news about Demi, she was very upset and emotional," a source told E! News.
"Selena has reached out to Demi's family members to share her love and prayers, and she is really distraught about her health," the source says. "She hates that Demi has been suffering."
Selena's mother Mandy Teefey, also shared a sweet Instagram post writing, “This was exactly 10 yrs ago at S, Sweet 16. @ddlovato we love you,” Mandy writes. “The world is a better place because of these infectious smiles. My heart hurts.”