"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," Timberlake wrote. "When I first got the diagnosis I was shocked for sure.

Lyme disease is caused by bacteria spread through the bite of infected ticks. Symptoms include rash, fever, headache, extreme fatigue, stiffness in joints, muscle aches or weakness, according to the Mayo Clinic.

As revealed in a vulnerable Instagram post just one day after his final show, the pop superstar had long been suffering from nerve pain and severe fatigue caused by Lyme that made him question whether he should stop touring.