Pop superstar Justin Timberlake has revealed that he was diagnosed with Lyme disease after wrapping up his two‑year Forget Tomorrow World Tour, disclosing for the first time the physical toll the illness took behind the scenes on social media Thursday afternoon.

The 44‑year‑old revealed in an emotional Instagram post that he has been quietly battling Lyme disease, a condition he described as “relentlessly debilitating, both mentally and physically.”

Reflecting on the conclusion of his tour, the singer said he wanted to open up about his health struggles after months of pushing through nerve pain, fatigue and sickness on stage.

“When I first got the diagnosis, I was shocked for sure,” Timberlake wrote. “But at least I could understand why I would be onstage and in a massive amount of nerve pain or just feeling crazy fatigue or sickness.”

The Grammy-winning artist explained that he faced a choice between halting his tour or continuing despite the pain.

“I decided the joy that performing brings me far outweighs the fleeting stress my body was feeling,” he wrote, adding that he is now striving to be more transparent about his personal struggles to avoid misinterpretation and to “help others experiencing this disease too.”

“Here’s wishing JT a quick recovery. He’s one of the great live acts on the road these days, with a catalog of great songs to play for fans,” said Michael Norman, life and culture editor for cleveland.com and The Plain Dealer.

Lyme disease is a bacterial infection transmitted to humans through the bite of infected blacklegged ticks, commonly called deer ticks, according to the Centers for Disease Control and Prevention. The illness is most prevalent in the Northeast, upper Midwest and Pacific Coast, though cases have been reported across the U.S.

According to Mayo Clinic, early symptoms can include fever, fatigue, headaches and a characteristic “bull’s-eye” skin rash known as erythema migrans. Without treatment, Lyme disease can spread to joints, the nervous system and the heart, leading to long-term complications such as chronic pain or neurological problems.

According to Johns Hopkins Medicine Lyme Disease Research Center, lingering effects, often referred to as post-treatment Lyme disease syndrome, can persist for months or years.

The best prevention is avoiding tick bites. Health experts recommend wearing long sleeves and pants in wooded or grassy areas, using repellents that contain DEET and conducting thorough tick checks after being outdoors, the CDC said.