Adam Devine was told last year he was "dying"

Speaking on the 'In Depth with Graham Bensinger' podcast, he said: "I was having spasms all over, and I still kinda do.

"They don't really know [why], for a while they told me I was dying. Literally within this last year they told me that.

The 41-year-old star's medical team thought he had stiff person syndrome (SPS) and told him it wouldn't leave him with much time left to live, despite death from the condition being rare.

He said: "[I was told] the average life expectancy is six years for someone who has it, and they told me that I had that literally a month before my son Beau was born."

But Adam visited "the guy who coined the phrase stiff-person syndrome," and was told his struggles were more likely to stem from his childhood accident than a new condition, though the spasms were still deemed "unexplainable".

Despite his struggles, the 'Righteous Gemstones' actor has seen his health improve recently and a stem cell treatment has left him feeling "the best" he has been "for the past three years".

Adam believes getting physically fit with CrossFit and cycling during the COVID-19 pandemic may have triggered the pain in his body.

He said: "I think I just got so tight and so tightly wound, and my body has all these things that are a little wonky and a little wrong with it, that I just sort of snapped. I think I'm still dealing with it, but it's been three years now."

Adam previously told how he was hit by a truck following a miscommunication with his friend.

He told Entertainment Weekly: "I was hit by a cement truck. We were gonna go get candy. And also rip pages out of Penthouse. That was a real agenda.

"[We left the store and] one buddy was across the street. He yelled 'Come on!' as in 'I'm excited to go look at boobs!' And I heard 'Come on!' as in 'The coast is clear!'"

The comic walked with his bike into the road and straight into the path of the truck.

He added: "They say the reason I lived was the bike took the hit first. I still slid 500 feet. Picked me up under the first two wheels and then spit me out."