Bella Hadid contracted Lyme disease likely from exposure to infected ticks while living in an environment conducive to tick bites. She, her mother Yolanda Hadid, and her brother Anwar were diagnosed with Lyme disease around 2013. The family lived on a horse ranch in Santa Barbara for about 10 years, spending much time outdoors in nature, which is a common setting for tick exposure. Lyme disease is caused by Borrelia bacteria transmitted through tick bites, and it is not genetic; multiple family members can be affected due to shared environments rather than heredity. Bella has shared that the disease has caused her significant health challenges over many years, including severe fatigue, neurological symptoms, and flare-ups linked to infections such as dental infections. Her condition has involved extensive medical treatment over long periods.