(NewsNation) — Fresh off his world tour, Justin Timberlake shared new information about his health: He has Lyme disease.  

The singer wrote a post on Instagram on Thursday revealing the news while also reflecting on his “The Forget Tomorrow World Tour.”  

“Well, as these two incredible years come to an end and I look forward to the future, I wanted to write something from the heart,” Timberlake wrote. “This has been the most fun, emotional, gratifying, physically demanding, and, at times, grueling experience.”  

The “Mirrors” singer said that despite being a private person, he wanted to give an update on his health.  

“I’ve been battling some health issues, and was diagnosed with Lyme disease — which I don’t say so you feel bad for me –– but to shed some light on what I’ve been up against behind the scenes,” he said. “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 said he was “shocked” to learn he contracted the disease, but it finally gave him an answer to why he was fatigued, sick and in a “massive amount of nerve pain” while he performed.  

What is Lyme disease, and how does it spread?  

Lyme disease is a bacterial infection caused by bacteria or other toxins entering the body and multiplying. Strep throat, E. coli, salmonella and impetigo are among the most common of these. While they share many symptoms with viral infections, bacterial infections don’t always cause disease. 

In North America, Lyme disease is usually caused by ticks, which get infected by feeding on the blood of rodents. They pass it on when they latch on to another animal, including humans. 

As for the “Rock Your Body” singer, he added in his IG post that he is “sharing all of this with the hope that we can all find a way to be more connected. I’d like to do my part to help others experiencing this disease too.” 

NewsNation’s Rich Johnson contributed to this report.