(KTLA) — Singer Justin Timberlake has just wrapped up his Forget Tomorrow World Tour and gave his fans a major update on his health.

In a lengthy post on Instagram Thursday morning, the singer got personal.

“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. It’s not an easy task to try to contextualize the whirlwind of touring –– but, I will try…” he wrote. “This has been the most fun, emotional, gratifying, physically demanding, and, at times, grueling experience. I have been doing this for 30+ years (which feels crazy to say) –– and have given all that I have to this. I could not have done it without my family, friends, The TN Kids, and all of YOUR support.”

He then went on to explain that while he’s “a pretty private person,” as he was on the road, he wanted to tell his fans “a little bit” about what’s been going on with him.

“Among other things, 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. 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 revealed.

The “SexyBack” singer explained that he was shocked when he was first diagnosed with the disease, but it helped him understand why he’d feel “a massive amount of nerve pain” and “crazy fatigue or sickness,” especially when he was onstage.

“I was faced with a personal decision. Stop touring? Or, keep going and figure it out. I decided the joy that performing brings me far outweighs the fleeting stress my body was feeling. I’m so glad I kept going,” he continued. “Not only did I prove my mental tenacity to myself but, I now have so many special moments with all of you that I will never forget. I was reluctant to talk about this because I was always raised to keep something like this to yourself. But I am trying to be more transparent about my struggles so that they aren’t misinterpreted.”

In sharing this, he hopes it can help everyone “find a way to be more connected.”

“I’d like to do my part to help others experiencing this disease too.”

The recent tour was the former *NSYNC singer’s seventh headlining concert tour and the first one in five years. It followed the release of his sixth studio album, “Everything I Thought It Was.”

According to the Mayo Clinic, Lyme disease is caused by Borrelia bacteria, typically carried by ticks. Symptoms come in stages.

Stage 1 symptoms include:

• Fever.
• Headache.
• Extreme tiredness.
• Joint stiffness.
• Muscle aches and pains.
• Swollen lymph nodes.

Stage 2 includes Stage 1 symptoms and the following:

• Many rashes on other parts of the body.
• Neck pain or stiffness.
• Muscle weakness on one or both sides of the face.
• Immune-system activity in heart tissue that causes irregular heartbeats.
• Pain that starts from the back and hips and spreads to the legs.
• Pain, numbness or weakness in the hands or feet.
• Painful swelling in tissues of the eye or eyelid.
• Immune-system activity in eye nerves that causes pain or vision loss.

“In the third stage, you may have symptoms from the earlier stages and other symptoms. This stage is called late disseminated disease,” the Mayo Clinic said. “In the United States, the most common condition of this stage is arthritis in large joints, particularly the knees. Pain, swelling or stiffness may last for a long time. Or the symptoms may come and go. Stage 3 symptoms usually begin 2 to 12 months after a tick bite.”