Selena Gomez suffering from Lupus.

In an interview in Radar Online, Selena's grandfather, Ricardo Gomez, confirmed that Selena is suffering from a serious disease called Lupus. But he assured fans of the teen icon that she is currently receiving treatment and is doing well.

Ricardo shared that Selena already knew about the lupus a few years back.

Several factors like Selena's unforgiving work schedule, her rehab stint, and even her off and on relationship with the Biebs have contributed to the star's struggle with the lupus disease

"What worries (us) more is that she doesn't know how to say no. She won't take time for herself to relax, to eat well," Ricardo shares.

"She was working a lot. She was exhausted. She hardly takes some time out. There was some pressure, first because it's a lot of work...she was worried a lot about Justin."

Ricardo also expressed his feeling of disinterest and indifference towards Justin Beiber:

"He was just a nice little fella. Totally different from what he is right now. ... It just makes me feel upset because he used to be a real nice boy."

Selena who was in rehab earlier this year has not seen her grandfather since September because of her very busy schedule. Ricardo expressed that the young star should really take time to rest and get well.

"The doctor was telling her she needs to take some time out...It's just too much pressure what she's going through. It's just too much! She doesn't have a single day's break. It's getting to the point with all this pressure, that it's too much," he adds.

According to Mayo Clinic, "Lupus is a chronic inflammatory disease that occurs when your body's immune system attacks your own tissues and organs. Inflammation caused by lupus can affect many different body systems - including your joints, skin, kidneys, blood cells, brain, heart and lungs."