Currently, nothing has been confirmed about what is causing Wendy's particular health issues right now. She hasn't said anything about it publicly, but she does have the autoimmune disorder Graves' disease. According to the Mayo Clinic, it is "an immune system disorder that results in the overproduction of thyroid hormones (hyperthyroidism)."

Wendy has been open about having Graves' disease and other things she's experienced. In February 2018, she said on her show that her fans had seen an issue with her eye before she did. She said that the disease squeezes the muscle behind her eye and that's what people were seeing.