Ashton Kutcher's secret health battle: 'Lucky to be alive'

Ashton Kutcher has shocked fans by revealing he suffered from an auto-immune disorder that left him unable to see, hear or walk.

In a sneak peek of Running Wild with Bear Grylls: The Challenge obtained by Access Hollywood, the 44-year-old shared, "Like two years ago, I had this weird, super rare form of vasculitis that, like, knocked out my vision, it knocked out my hearing, it knocked out, like, all my equilibrium".

He added that it took about a year before he was back to normal again.

Vasculitis is a very rare auto-immune disorder that can cause blood vessels to become inflamed, restricting blood flow. It can either be a short-term or long-lasting condition and can lead to organ and tissue damage.

RELATED

• Anne Heche in a coma after car crash: 'Extreme critical condition'

• Olivia Newton-John's final post days before her tragic death

• John Travolta's devastating tribute to Olivia Newton-John: 'I love you'

"You don’t really appreciate it until it’s gone," he told Grylls. "Until you go, 'I don’t know if I’m ever going to be able to see again, I don’t know if I’m ever going to be able to hear again, I don’t know if I’m ever going to be able to walk again.'

"[I’m] lucky to be alive," he added.

After his health scare, Ashton said that he doesn't let any challenge stand in the way of his success, "The minute you start seeing your obstacles as things that are made for you, to give you what you need, then life starts to get fun, right?"

"You start surfing on top of your problems instead of living underneath them."

Bear responded, "What do they say in survival? Storms make you stronger. And I think he’s living proof of that."

Ashton, who met his wife Mila Kunis when they were both working on That '70s Show, recently shared that the pair reprised the roles in the Netflix spinoff That '90s Show.

"Mila and I were contemplating it," he told Variety last month. "We thought, 'Listen, we’re only in the position that we’re in because of that show, so let’s just go back and do this.' We just went back and had fun for a week. It was so random and fun."

Never miss a thing. Sign up to Yahoo Lifestyle’s daily newsletter.

Or if you have a story idea, email us at lifestyle.tips@yahooinc.com.