Christina Applegate says she was misdiagnosed with MS: 'I'm back at square one'

Christina Applegate spent five years as one of the most visible faces of multiple sclerosis. On Tuesday, Oct. 20, she said doctors now believe she never had it. The news sent her name past 200,000 searches in the US, according to Google Trends, and the top related queries were blunt: “what does Christina Applegate have?” and “Christina Applegate misdiagnosed MS.”

The short answer, based on her own account: doctors have ruled out MS, and they haven’t yet given her another diagnosis.

What Christina Applegate said on MeSsy

Applegate shared the news in a two-part episode of MeSsy, the podcast she co-hosts with actress Jamie-Lynn Sigler, who has MS, CBC News reported. She explained that she had stepped away from the show for some months, partly to process what she had learned.

“To me it comes as, like, I’m back at square one,” she said.

According to CBC, her doctor congratulated her when delivering the news, but Applegate said she felt lost rather than relieved. “You don’t get misdiagnosed and all of a sudden I’m better. I haven’t gotten better … if anything, I’ve gotten worse, in some ways,” she said. “My legs aren’t working, you know, all the same stuff is happening to me.”

How she was first diagnosed with MS

Applegate first announced her diagnosis on social media in August 2021. She said on the podcast that her symptoms began earlier that year with numbness in her feet that slowly moved up her legs, followed by pain. She went through spinal and brain MRIs and a spinal tap, CBC reported, and doctors initially thought she might have a low-grade form of the disease. When they found nearly 40 lesions on her brain, she was formally diagnosed.

“I felt like, ‘OK, I have an answer,’” she said.

Why doctors changed their minds

According to Applegate’s account as reported by CBC, a couple of years ago her doctor paused her infusion treatments to see how her B cells would respond. When the levels didn’t change, doctors took a closer look at the diagnosis, including with “new technology that had come out” for brain MRIs.

CBC noted that the official diagnostic criteria for MS were updated in 2024, in part to reflect advanced MRI tools that can detect the disease more precisely. Applegate did not say which specific finding changed her doctors’ minds, and we don’t know beyond what she shared.

So what does Christina Applegate have?

No new diagnosis has been announced. CBC reported that she was not given another diagnosis to replace MS, which leaves her without an explanation for her continuing symptoms.

“It’s like I had a reason … for why my day sucked every day, and now I don’t have a reason. It’s very unnerving,” she said. Tearfully, she told Sigler, “I feel like I let everybody down,” because the two had become, in her words, “the poster children for MS.”

Sigler told her that her advocacy still mattered. “I’m going to continue holding in my heart that this is a blessing for you,” she said.

How common is an MS misdiagnosis?

More common than many people assume. CBC cited a 2019 Cedars-Sinai study that found a misdiagnosis rate of nearly one in five patients at the centers studied, and a 2024 review that pooled six studies and estimated about 15%. Individual studies have reported rates anywhere from 5% to 41%, so the true figure varies a lot by setting.

Dr. Mark Freedman of The Ottawa Hospital told CBC that MS can be hard to pin down because other conditions, such as migraines, can also leave spots on brain MRIs. He warned that some aggressive MS treatments suppress the immune system, which carries real risks if a patient doesn’t actually have the disease.

This is general information, not medical advice. Anyone questioning a diagnosis should talk with their neurologist.

FAQ

Does Christina Applegate have MS? According to Applegate, her doctors now say she does not.

What does she have instead? No new diagnosis has been made public, and her symptoms continue.

Where did she announce it? On MeSsy, the podcast she co-hosts with Jamie-Lynn Sigler, in an episode released Oct. 20.

When was she originally diagnosed? She announced the MS diagnosis in August 2021.