Ashton Kutcher has revealed he was diagnosed with a rare autoimmune disorder nearly two years ago that left him unable to see or hear for an extended period of time.
“Like, two years ago, I had a weird, super-rare form of vasculitis that knocked out my vision, knocked out my hearing and knocked out all my equilibrium,” the actor said on a new episode of National Geographic’s “Running Wild With Bear Grylls: The Challenge,” according to an excerpt obtained by Access Hollywood.
“It took me like a year to build it all back up. You don’t really appreciate it until it’s gone, 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.’”
“Lucky to be alive,” he added.
Vasculitis is the name of a group of rare autoimmune diseases that cause inflammation of blood vessels, according to the Mayo Clinic. It can lead to thickening of the walls of blood vessels, restricted blood flow and damaged organs and tissues. The condition might affect just one organ or several, and it can be short-term or long-lasting.
When affecting the eyes and ears, symptoms can include abrupt hearing loss, double vision or temporary and permanent blindness in one or both eyes, the Mayo Clinic reports.
The exact cause of vasculitis isn’t fully known, but some types have been linked to genetics while others occur when the immune system attacks blood vessels by mistake after being triggered by other diseases or infections.
“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,” Kutcher said of facing adversity. “You start surfing on top of your problems instead of living underneath them.”
This article originally appeared on HuffPost and has been updated.