Poor Gigi Hadid.

The young model opened up in a new interview about her battle with Hashimoto’s disease, which is described by WebMD as "an autoimmune disease, a disorder in which the immune system turns against the body's own tissues. In people with Hashimoto's, the immune system attacks the thyroid."

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"My metabolism actually changed like crazy this year. I have Hashimoto's disease. It's a thyroid disease, and it's now been two years since taking the medication for it, so for the Victoria's Secret show I didn't want to lose any more weight, I just want to have muscles in the right place, and if my butt can get a little perkier, then that's good," she told Elle.

Other stars who suffer from the disease are Gina Rodriguez, Zoe Saldana and Victoria Justice.

Gigi is not the only one in her family who suffers from illness. Her mother, Yolanda Hadid, and siblings, Bella and Anwar, all battle Lyme disease.