Christina Applegate Says She Was Misdiagnosed With MS After Yearslong Battle. Years after Christina Applegate shared that she was battling multiple sclerosis, the actress said she is "back at square one" after learning she had been misdiagnosed. Christina Applegate is left with more questions than answers about her health. More than five years after the Married... with Children alum spoke out about her battle with multiple sclerosis, she learned that she was misdiagnosed. "This may come as great news, but to me it comes as, like, I'm back at square one," Applegate said on the Oct. 20 episode of her and Jamie-Lynn Sigler's MeSsy podcast. Recalling her doctor's visit, she added, "She came into my room and said, 'Congratulations, you don't have MS.' I was, like, not happy at all. Everybody else was so happy." The 54-year-old emphasized that the confirmation of the misdiagnosis hadn't changed how she's continued to struggle physically, still regularly using a walking cane and experiencing pain and aches all over her body. "I haven't gotten better, Jamie," she said. "If anything, I've gotten worse. So I'm back at square one where I don't know what's going on with me. 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." "I have every symptom of someone with MS," she continued. "Every single one. Now, we both know that there are many things that mirror MS. Many different things." Applegate -- mom to 15-year-old daughter Sadie with husband Martyn LeNoble -- shared insight into her mental health struggles after learning that she does not have the degenerative chronic autoimmune disorder. "I'm sitting here having slept all day yesterday feeling like absolute crap because of the heat," she said. "My legs aren't working. All the same stuff is happening to me. And yet I have this thing of like, 'Well, you don't have that, so maybe you're faking it' in my head." The Dead to Me actress admitted that she also feels guilty since she had found immense support among others suffering from MS. "I leaned into other friends," she noted. "I leaned into the community. I felt safe because I had a place to talk, which was here felt like, 'OK, I have an answer. What a great thing. I may not get out of this. I might get worse, but I'm taking all the necessary precautions.'" "It's weird because I feel like I let everybody down," Applegate shared. "It's this weird feeling because I became this, you and I: the poster children for MS. Everything I was doing, I had a reason. I had a f--king reason as to why my day sucked every day. And now I don't have a reason. It's very unnerving, and it's very confusing for me." Sigler -- who was diagnosed with MS in 2002 at age 20 while working on The Sopranos -- empathized with Applegate's frustrations. "It brings up an interesting point that we can talk about," she said, "the labeling of things and how attached we become to them for so many reasons. It feels like there's a road map, at least, that you have for things." "We've come to learn that this is not a rare occurrence," Sigler continued of medical misdiagnoses, "especially when it comes to MS." A 2019 study led by Cedars-Sinai found that nearly one in five patients with "an established diagnosis" were misdiagnosed. Sigler, 45, also urged her co-host not to feel as if she's at fault for her current situation. "Everything you did and shared and were and are to so many people doesn't go anywhere," she added. "This new information that you have in your life, that doesn't take away anything that you did. You didn't mislead anyone."