Gigi Hadid is opening up about her sister Bella Hadid’s treatment for Lyme disease.

On Tuesday, Gigi, 28, posted on her Instagram Story to explain a throwback picture she had shared with her sister, 26,

backstage at a fashion show last month with the caption, "Can't wait 4 the comebaccckkkkkk.” 

"Just wanna touch on this post from last week,” Gigi wrote. “Bella just finished a long and intense treatment for Lyme disease.

Didn't want some to take my post as a promise she'll be back for shows this next season…).

As well as clarifying her previous post about her supermodel sibling, Gigi added,

"I'm so proud of her and excited for her  ✨comeback✨ whenever she feels ready 😊x.”

Bella was diagnosed with Lyme disease in 2012 alongside her younger brother Anwar, 24,

and their mom, former Real Housewives of Beverly Hills star Yolanda, 59.

According to Mayo Clinic, symptoms of Lyme disease include fever, extreme tiredness, joint stiffness and swollen lymph nodes.