Actress Christina Applegate has revealed that she was misdiagnosed with multiple sclerosis (MS), a significant update following her public diagnosis in 2021. The 54-year-old star shared the surprising news on Tuesday during an episode of the podcast "MeSsY," which she co-hosts with Jamie-Lynn Sigler, who also lives with MS.

Applegate stated that her doctor informed her of the misdiagnosis, a revelation that has left her feeling disoriented and back at the beginning of her health journey. "This may come as great news, but to me, it comes as like, very like I'm back at square one," Applegate said on the podcast. She described the moment her doctor told her, "Congratulations, you don't have MS. Congratulations."

While the news might seem positive, Applegate noted that she continues to experience all the symptoms she previously associated with MS. "If anything, I've gotten worse in some ways, and so I'm back at square one that I don't know what's going on with me," she explained. The actress added that this situation necessitates an "online investigation" for her doctors to determine the cause of her persistent symptoms since 2021, describing the experience as "very unnerving and it's really confusing for me."

The implications of this misdiagnosis are profound for Applegate, who had publicly embraced her role as an advocate and public figure for the MS community. She admitted to feeling a sense of loss and confusion about her identity and purpose after this revelation. "It's weird because I feel like I let everybody down," the actress said, referencing her and Sigler's status as "poster children for MS."

Applegate first announced her MS diagnosis in 2021, a condition characterized by the immune system attacking the central nervous system. She spoke candidly about the difficulties of living with the disease, including in an interview with Robin Roberts in March, where she expressed that she had not yet accepted the diagnosis and referred to it as a "lifelong disease with no cure. Period."

She had taken a hiatus from her podcast to process the misdiagnosis, which she described as having plunged her into a "great depression." Applegate continues to rely on a wheelchair for mobility in certain situations, such as doctor's appointments, and stated that the news of not having MS did not magically resolve her physical challenges. "I still have to use wheelchairs when I go to the doctor’s office. I can’t walk from the car to the room. I’m still in this," she said.

Diagnosing MS typically involves a comprehensive evaluation, as there is no single definitive test. This process can include neurological exams, MRI scans, and laboratory tests. Symptoms of MS are varied and unpredictable, ranging from fatigue and numbness to weakness and bladder control issues.

Applegate's most recent major acting role concluded in 2022 with the Netflix series "Dead to Me." The misdiagnosis leaves her grappling with not only her physical health but also her sense of community and belonging, which she had found through her public advocacy for multiple sclerosis.