“Not anorexia, it’s a thyroid issue,” wrote the mom of two. “I don’t know what it says about me that I got this thin and didn’t think there was anything wrong.”
Mollen — who welcomed her second child, son Lazlo, last October — said that on Friday she discovered “a bulge” in her neck that inspired her to seek out a doctor.
“I’m STILL waiting on blood work but my doc thinks it’s Graves,” she said. “If you just had a baby and have lost an inordinate amount of weight, feel like you are on cocaine, are suddenly heat intolerant, and can’t stop losing hair, and feel like your husband is being a dick it might just be your thyroid!! Get checked.”
In the accompanying photo, Mollen, 38, posed naked and wrapped her arms around her body.
She also addressed the health scare on her Instagram story, revealing that he doctor said she won’t get her full testwork back until Sunday. “I can’t wait until Sunday,” said Mollen.
According to the American Thyroid Association, Graves’ disease is an autoimmune disease which can lead to overactivity in the thyroid gland. The Association said Graves’ disease is the most common cause of hyperthyroidism.
Mollen first opened up about her “rapid weight loss” on Friday, addressing her followers who had “written and asked” about her body change.
- Want to keep up on the latest from PEOPLE? Sign up for our daily newsletter to get our best stories of the day delivered straight to your inbox.
“Weight loss that to be honest, I couldn’t really explain until now,” she wrote on social media.
She asked her followers for advice if they’d struggled with similar rapid postpartum weight loss, writing, “Though I am not certain, I have good reason to believe it is some sort of hyperthyroidism. Apparently this is common in women AFTER PREGNANCY. “