Gigi Hadid Gets Emotional As It's Revealed Her Siblings Also Have Lyme Disease

The 20-year-old model teared up while discussing her family's difficult medical struggle.

In 2012, Real Housewives of Beverly Hills star Yolanda Foster was diagnosed with Lyme disease, and while accepting an award at the Global Lyme Alliance Gala in New York City on Thursday night, the former model revealed that she's not the only one in her family who suffers from the condition.

Yolanda revealed that her two of her three children -- Bella and Anwar Hadid – also have the disease.

Yolanda's daughter, model Gigi Hadid, spoke with ET at the event about the medical challenges her family is facing, and the 20-year-old model teared up when recounting their struggle.

WATCH: Yolanda Foster Says Ongoing Battle with Lyme Disease Is a ‘Nightmare’

"I'm the only one in, of my siblings, my mom and my family that hasn't been affected by Lyme disease," Gigi shared, getting choked up. "It's been really hard for me because I'm the only one that doesn't really understand it."

"What's been hardest for me is just trying to find a way to be their hope and kind of be a strength for them even with the disease that I can't understand fully because I haven't been through it," Gigi added.

One thing that helps with the struggle has been the family's ability to maintain close bonds, especially in the face of this medical adversity.

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"I mean my sister is my best friend, my mom is my best friend, my brother is my best friend," Gigi’s sister Bella added in support. "And you know when we need each other we're always there and you know automatically no matter what we have."

For more on Yolanda Foster's difficult battle against her debilitating Lyme disease, watch the video below.