Drinking wine isn't a huge deal — but if you're Selena Gomez, who is battling the autoimmune disease lupus and recovering from a kidney transplant, it is definitely complicated. Earlier this month, Selena was spotted buying a couple of bottles at a local Target, which has friends and experts really worried about her health.

"When we're talking about lupus and a kidney transplant, avoiding alcohol would be critical for her to stay well," Dr. Robert Fafalak, who doesn’t treat the star, tells In Touch exclusively. "Alcohol can be deleterious in terms of potential interactions with some of the medications she probably takes." The NYC-based lupus expert and rheumatologist also explained how wine can produce negative side effects such as stomach aches, which could complicate things.

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Attune Health rheumatologist Dr. Christine Lee also agrees but explains to Life & Style that while drinking in moderation might be acceptable in some cases, Selena, who’s also been to rehab for what she called "issues with depression and anxiety," should play it safe. "Oftentimes, it is recommended that alcohol be avoided due to interaction with anti-[organ] rejection medications," Dr. Lee, who also hasn’t treated Selena, adds.

And experts aren't the only ones who are concerned. Friends are also worried — especially since alcohol is a known depressant. "The mere thought that Selena could be drinking," an insider tells In Touch, "has friends worried for her health and well-being."

Since her kidney transplant, Selena, 25, has been mostly out of the spotlight and recently split with on-again, off-again boyfriend Justin Bieber, which was sparked by her mom's distrust of the pop singer. "There has been so much bad blood between them," a source told In Touch about Justin and Mandy Teefey's relationship. "Selena has told Justin that it's his responsibility to make things right, no what it takes." However, according to the insider, "Justin doesn't even know where to begin with Mandy." Stay strong, Selena!

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