Lyme disease is a medically recognized infection that can cause pain, fatigue and muscle aches. But many celebrities — including Hadid, American singer Justin Timberlake and Canadian singer Justin Bieber — who claim they have Lyme appear, on a closer look, to be describing chronic Lyme disease, a condition that isn’t recognized by conventional medicine.

It's a controversial term used by some alternative practitioners to describe pain, fatigue and neurological symptoms they attribute to a persistent Lyme infection. Often, patients have never tested positive through a regulator-approved Lyme disease test.

Despite the shaky validity, identifying otherwise-unexplainable symptoms as chronic Lyme can seem like a path toward getting better, Dr. Paul Auwaerter, a professor at the Johns Hopkins University School of Medicine, told CBC News.

“They are looking for answers to something that many times they get short shrift from their regular physicians or from consultants.”

The disease is on the rise globally, including in Canada. There were 5,809 reported cases of Lyme disease in this country in 2024, according to the Public Health Agency of Canada. It has been trending upward nationally since 2009, according to Health Canada — in part due to climate change and a greater awareness among the public and doctors.