Imagine Dragons Frontman Dan Reynolds Reveals He Has 'Debilitating' Chronic Disease

The band Imagine Dragons has spent a lot of time at the top of the charts, but frontman Dan [...]

The band Imagine Dragons has spent a lot of time at the top of the charts, but frontman Dan Reynolds reveals their rise to stardom was almost derailed due to a serious health condition.

Reynolds shared that when he was 21 he began experiencing "debilitating" pain in his back, which prevented him from lifting heavy objects and performing.

"It was beyond the pain that you feel when it's just a back ache. It felt like someone was drilling my nerves," he recalled to PEOPLE. "It was right when the band was starting to have minor success — we were starting to sell out small clubs, and we were playing these very active shows and it started to make me have to cancel shows."

"I couldn't get on stage. I couldn't move, I couldn't sleep at night, I couldn't perform without standing perfectly still. I couldn't sit down for more than a half an hour," he continued.

After months of failed diagnoses and treatments, the singer was found to be suffering from Ankylosing spondylitis, often referred to as AS. AS is a chronic inflammatory condition of the joints, which can even lead to spinal fusion in the worst cases.

"I went, and then they did the test to see if it's in your genes — which it was, because it's an autoimmune disease," he said. "And then they diagnosed me and put me on a treatment plan, which fixed me almost immediately. Which was another sign that that's what it was."

For the past few years, the singer has been quiet about the health struggles he has faced.

"I was shy to reveal it because it made me feel like something was wrong with me, or — to say the word disease, it's such a drastic sounding word," he explained. "And I didn't want to admit to myself, or to anybody, that I was struggling with a disease."

Now he is using his place in the spotlight to raise awareness about AS and empower others who are dealing with chronic conditions.

"I have a chance to really raise awareness and help people that are just becoming diagnosed to see that there's actually light at the end of the tunnel," he said while promoting his new project, This AS Life Live!, which is working in partnership with the Spondylitis Association of America (SAA) and Novartis to give people an honest look at the disease.

"For me, I really wish that there was a place that I could have gone to where I was seeing a direct community. People talking and saying, 'These are the things I'm feeling. These are the ways that I'm combatting it, and it's working for me."

Now a father of three, the artist is glad to be able to perform, but also be able to pick up his children. While things have improved, Reynolds said the condition is a "constant and life-long battle."

"There's not a day that goes by that I'm not combatting it in some way," he said.