Justin Timberlake is opening up about a "debilitating" medical issue.

The singer, 44, revealed he has been "battling some health issues" and was diagnosed with Lyme disease.

"If you've experienced this disease or know someone who has — then you're aware: living with this can be relentlessly debilitating, both mentally and physically," he wrote in an Instagram post on Thursday, July 31. "When I first got the diagnosis I was shocked for sure. 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."

Timberlake said that the diagnosis led him to consider whether to stop touring, but he "decided the joy that performing brings me far outweighs the fleeting stress my body was feeling." He added, "I’m so glad I kept going."

The Grammy winner shared the revelation as he reflected on the end of his Forget Tomorrow World Tour, which kicked off in 2024. He described the tour as the "most fun, emotional, gratifying, physically demanding, and, at times, grueling experience."