Christina Applegate Launches ‘Investigation’ Into Health Battle After MS Misdiagnosis

Christina Applegate is looking for answers.

The actress shockingly revealed that she was misdiagnosed with multiple sclerosis, and now she is launching her own “investigation” to learn exactly what is going on.

“For the physical self, I’m doing PT three times a week and gonna start the investigation now next week,” Applegate said on the Tuesday, October 20, episode of her and Jamie Lynn Sigler’s “MeSsy” podcast. “That’s kind of how new this all is, is that we haven’t even started the investigation. Because it was kind of left up to me to kind of figure it out.”

“I’m like, ‘I don’t know. How many specialists am I going to find for something I don’t even know what I’m looking for?’ That process is going to start,” she added.

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When Did Christina Applegate Find Out About MS Misdiagnosis

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The actress went public with her MS diagnosis and battle in 2021, but detailed the moment she learned that was actually not what she was dealing with.

“[My doctor] came into my room and said, ‘Congratulations, you don’t have MS,’” Applegate said on the podcast. “I was, like, not happy at all. Everybody else was so happy.”

And with that, she explained that there was no relief when she learned the news. Instead, she was left with more questions as she was still struggling with different symptoms.

“You don’t get misdiagnosed and then all of the sudden I’m better,” she said. “I haven’t gotten better, Jamie! If anything, I’ve gotten worse. So I’m back at square one where I don’t know what’s going on with me. And that’s going to be an online investigation that my doctors are going to be getting into just to find out what has been going on since 2021, why did this happen?”

On the episode, Applegate and Sigler also welcomed Dr. Marwa Kaisey, an associate professor with the Cedars-Sinai Medical Center department of neurology, who explained that misdiagnoses are “fairly common” because “we don’t have one single test for MS.”

“It’s not like we have something like a pregnancy test that says, ‘Yes, you have it. No, you don’t.’ It’s a list of criteria,” Kaisey explained. “Almost one in five of these people who’d been told they had MS, some for decades, didn’t actually have it. And a majority of them were on medication to treat their MS.”

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Christina Applegate Expresses She Feels Like She ‘Let Everybody Down’

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In the episode, Applegate further expressed how she felt like she “let everybody down” when she learned MS wasn’t the correct diagnosis.

“It’s weird because I feel like I let everybody down,” she said. “It’s this weird feeling because I became this — you and I, the poster children for MS. And everything I was doing. I had a reason. I had a f***ing reason as to why my day sucked every day. And now I don’t have a reason and it’s very unnerving and it’s very confusing for me.”

Applegate released a memoir earlier this year, on March 3, 2026, which was titled You With Sad Eyes, in which she detailed her MS battle.