Celebrity

‘Alias’ Star Explains Sudden Hair Loss

“I think I probably had it dormant in my body for a long time,” the actor explained.

(Photo by Scott Garfield/Disney General Entertainment Content via Getty Images)

Greg Grunberg is sharing a new health update with fans after experiencing sudden hair loss due to alopecia.

The Alias actor, 58, took to YouTube on Wednesday to address the concerned comments he’s been receiving from followers who have noticed his recent lack of hair.

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“First of all, I want to thank everybody who’s asking if I’m okay, you know, ‘What’s going on? I saw pictures of you, you have no hair, what’s happening?’ Well this is what’s happening,” the Heroes actor said in the video. “I, all of a sudden, got alopecia and I knew nothing about it. I’m still learning about it.”

Alopecia is an autoimmune disease that causes hair loss. There is no cure for alopecia, but some people can regrow their hair with treatment, according to the American Academy of Dermatology Association.

Grunberg can’t know the origin of his alopecia, but theorized it was triggered when he underwent a knee replacement surgery in October, which he thinks “shocked the alopecia into, you know, actually presenting itself.” He explained, “I think I probably had it dormant in my body for a long time.”

Grunberg also has Hashimoto’s disease, an autoimmune disease that impacts the thyroid, which he thinks could have combined with the pain medication he took for his surgery to trigger the presentation of alopecia.

Greg Grunberg at the Duster Series Premiere at Universal Studios on May 8, 2025 in Universal City, CA (Kathy Hutchins/Shutterstock)

“What I’ve learned in this immediate, you know, just doing the googling and the searching and going on all these chat groups and everything, is millions of people have this,” Grunberg explained. “And I look good! I mean, I’m lucky, all right? I look good.”

The actor revealed that the bald head is “the new look you’re going to see,” adding, “I don’t really care, but I just wanted to address this so you know what’s going on.” Grunberg concluded by saying that everything else about his health “checks out” and thanking his loved ones for their support.

“All my tests are coming back negative, my numbers are down, I’m eating right, I’m exercising, I’m doing all the right stuff,” he said. “No need to worry, everything is good… So thank you, I love you all. Thank you so much for all of your concern and your questions. It’s alopecia and a lot of people have it and a lot of people — most people — live well with it, so that’s what I’m doing, getting ahead of it.”