Ashton Kutcher said he is "lucky to be alive" after battling a "weird, super rare form of vasculitis," an autoimmune disorder that hindered his ability to walk, see, and hear normally. 

Ashton Kutcher says he is 'lucky to be alive' after battling a rare autoimmune disorder

In a preview of an upcoming episode of National Geographic's "Running Wild With Bear Grylls: The Challenge," Kutcher spoke about his battle with a rare autoimmune disease.

"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," Kutcher told Bear Grylls, the show's host.

"You don't really appreciate it until it's gone, until you go, 'I don't know if I'm ever gonna be able to see again. I don't know if I'm gonna be able to hear again, I don't know if I'm ever going to be able to walk again,'" Kutcher added.

According to Kutcher, it took around a year for him to recover from the condition. "I'm lucky to be alive," he said.

In the episode preview, Grylls referred to Kutcher's experience with vasculitis as "a terrifying journey," that made him strong and resilient. "What do they say in survival? Storms make you stronger, and I think he is living proof of that," Grylls added.

What you need to know about vasculitis

According to Mayo Clinic, vasculitis is an autoimmune disorder that involves "inflammation of the blood vessels." The inflammation can cause the walls of blood vessels to thicken, restricting blood flow and damaging organs and tissues.

There are multiple types of vasculitis, which can impact a single organ or several. Depending on the type of vasculitis, the disorder can either be temporary or long-term.

While it is unclear which type of vasculitis Kutcher suffered from, all forms of the condition cause swelling in the blood vessels and can trigger a variety of symptoms, including fever, weight loss, loss of appetite, fatigue, rashes, and pain, according to the NIH.

Experts do not fully understand what causes the condition. It can affect people at any age, but some types are more prevalent in different groups. Family history can also play a role in some types of the condition.

According to NIH, certain medications can increase a person's risk of developing vasculitis, including hydralazine, levamisole, and propylthiouracil. In addition, people who smoke and use drugs may also face an increased risk of the disorder.

Other health conditions, including autoimmune disorders like lupus, rheumatoid arthritis, and scleroderma, as well as Hepatitis B or C, and lymphoma can also increase a person's risk of developing the condition.

Typically, treatment depends on the condition's severity. However, NIH noted that symptoms can sometimes be treated with over-the-counter medicine in mild cases. In more severe cases, prescription medications are often required to balance the immune system, decrease swelling, or increase blood flow. Some people with vasculitis may also require surgery, particularly if arteries become blocked.

"If you are diagnosed with vasculitis, medicine can help improve your symptoms and help you avoid flares and complications. If vasculitis responds to treatment, it can go into remission, a period of time when the disease is not active," according to NIH. (Cheng, Washington Post, 8/9; Davis, NPR, 8/9; Pitofsky, USA Today, 8/9)