What does Christina Applegate have? Actress reveals she was misdiagnosed with MS

Christina Applegate has revealed a surprising development in her health battle: after five years of believing she had multiple sclerosis (MS), the actress says doctors have determined that her original diagnosis was incorrect. However, the 54-year-old star continues to experience debilitating symptoms, and the exact cause of her condition remains unknown.

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The Dead to Me and Married… with Children actress shared the news on October 20, 2026, during an emotional episode of her MeSsy podcast, which she co-hosts with actress Jamie-Lynn Sigler, who has lived with multiple sclerosis for more than two decades.

Applegate explained that a doctor recently informed her that she does not have MS, contradicting the diagnosis she publicly announced in 2021. Rather than feeling relieved, the actress described experiencing confusion, frustration and uncertainty about her future.

“I’m back at square one where I don’t know what’s going on with me,” Applegate told listeners.

What illness does Christina Applegate have now?

As of October 20, 2026, Christina Applegate has not publicly confirmed a new medical diagnosis to explain her ongoing health problems.

Although doctors have reportedly ruled out multiple sclerosis, she continues to experience severe physical limitations similar to those associated with the neurological disease.

The actress explained that the change in diagnosis has not resulted in any improvement in her condition.

“You don’t get misdiagnosed and then all of a sudden I’m better,” she said during her podcast.

Applegate added that her health has deteriorated in some respects, despite the revised medical assessment.

Over the past several years, she has publicly discussed chronic pain, extreme fatigue, mobility difficulties and other symptoms that have significantly affected her daily activities.

The actress also revealed that she continues to need a wheelchair for medical appointments because walking even short distances can be extremely difficult.

Her doctors are now investigating other potential explanations for her symptoms.

Why was Christina Applegate misdiagnosed with multiple sclerosis?

Applegate initially announced her MS diagnosis in August 2021, revealing that she had been dealing with a chronic neurological condition while working on the Netflix series Dead to Me.

For approximately five years, she underwent treatment and adjusted her professional and personal life around the diagnosis.

However, additional medical evaluations eventually led doctors to reconsider their original conclusion.

During the MeSsy podcast, neurologist Dr. Marwa Kaisey of Cedars-Sinai Medical Center explained that diagnosing multiple sclerosis can be particularly complicated because there is no single definitive test capable of confirming the disease in every patient.

Instead, specialists generally evaluate neurological symptoms, magnetic resonance imaging (MRI) results, medical histories and other tests while ruling out conditions that produce similar symptoms.

Several illnesses can resemble MS, making an accurate diagnosis challenging even for experienced medical professionals.

According to medical experts interviewed about Applegate’s case, misdiagnosis is a recognized problem in multiple sclerosis care.

How did Christina Applegate react to her MS misdiagnosis?

The actress admitted that discovering the mistake was emotionally devastating rather than reassuring.

After years of treatment, public advocacy and adapting to what she believed was a lifelong illness, Applegate said the unexpected news left her without an explanation for her declining health.

She also expressed concern about disappointing people living with multiple sclerosis, particularly because she had become a prominent advocate for MS awareness.

Her podcast co-host Jamie-Lynn Sigler reassured her that the new diagnosis did not diminish her contributions to the MS community.

Applegate has used her public platform to discuss the physical and psychological consequences of chronic illness, including how serious health problems can affect personal relationships, independence and professional opportunities.

Her memoir, You With the Sad Eyes, published in 2026, also explores her health struggles and the profound changes they brought to her life.