Chicago Blackhawks captain Jonathan Toews shed light on why he didn't play during the 2020-2021 season on Wednesday.

In a video posted to Twitter, the 33-year-old Toews revealed a diagnosis of chronic immune response syndrome (CIRS).

"I just think there were a lot of things that just kind of piled up where my body just fell apart," Toews said. "So what they're calling it is chronic immune response syndrome, where I just couldn't quite recover and my immune system was reacting to anything that I did - any kind of stress, anything that I would do throughout the day. There was always a kind of stress response."

The Winnipeg native said that the lack timeframe on a potential return was discouraging.

"It took some time," Toews said. "That was the frustrating part, not knowing when or how we were going to get over the hump, but thankfully, I've got a great support team of people who helped me through it and I learned a lot about just the stress I've put on my body over the years."

Toews says that he's appreciated all of the support and felt bad over people's level of concern.

"A lot of people were worried and I definitely felt bad to a certain degree that people were that worried and thought it was really serious," Toews said. "But in the back of my mind, I knew that I would get through it; it was just a matter of time."

The three-time Stanley Cup champion acknowledges that he kept his condition under wraps, but welcomed all the well wishes. 

"I wasn't too vocal about the things I went through this year and definitely want to thank the fans, my teammates, the organization, [owner] Rocky [Wirtz], [general manager] Stan [Bowman], [head coach] Jeremy [Colliton] - the fans, especially," Toews said.

A two-time Olympic gold medalist with Canada, Toews says he intends to return for a 14th NHL season.

"I think that's the biggest thing - that you realize there's more to life than hockey," Toews said. "But I'm excited to get back to the United Center and play and just go out there and have fun. And I think my best is going to come through and I'm excited to get back in front of the fans."

In 943 career games, Toews has 345 goals and 470 assists.