Selena Gomez's grandpa has opened up about the 21-year-old pop star's struggles in a candid new interview with RadarOnline.com. He tells the website that Selena is in treatment for lupus which the body's immune system attacks its own tissues and organs. While she was allegedly diagnosed several years ago, Ricardo says that her condition has been exacerbated by her grueling work schedule and rollercoaster relationship with Justin Bieber. "What worries us is that she doesn't know how to say no," he says. "She won't take time for herself to relax, to eat well." GET WELL SOON Selena!!!