Selena Gomez lupus
Selena Gomez was diagnosed with lupus, an autoimmune inflammatory disorder which causes the immune system to attack its own tissues and organsGetty

Canadian singer Justin Bieber helped Selena Gomez during her struggle with lupus. The former Disney star had recently revealed that she had undergone chemotherapy for lupus.

In 2014, Gomez had cancelled the Australian and Asian leg of her tour, saying that she needed to spend some time with herself. Later it was revealed that she was suffering from the autoimmune disease Lupus. A source told Hollywood Life: "He would always tell her she's the most beautiful girl in the world, and that it wouldn't matter if she gained weight, lost her hair, or anything."

"He would make up little songs for her...and if they were both in L.A., he'd come over and order in her favorite foods from all the most expensive restaurants in Beverly Hills," the insider added.

"They have obviously had a lot of ups and downs in their relationship, but he really stepped up for her. That's not to say there haven't been plenty of other times when he was a jerk, but he knew she was struggling, and he wanted to let her know he was there for her," the source continued.

A source told the celebrity gossip website that Gomez was stressed before treatment, and feared that she would lose her hair. However, the Baby singer stood by her side and comforted her.

"Fortunately, she did not," the insider claimed. "And she had Justin to support her through the whole ordeal."

Gomez had recently opened up about her treatment for lupus to Billboard magazine. She said: "I was diagnosed with lupus, and I've been through chemotherapy. That's what my break was really about. I could've had a stroke. I wanted so badly to say, 'You guys have no idea. I'm in chemotherapy. You're assholes.' I locked myself away until I was confident and comfortable again."