Actor Christina Applegate said she was misdiagnosed with multiple sclerosis, a condition she believed she had for more than five years, NBC News reported. She revealed the news in a two-part episode of her podcast, "MeSsy," released Tuesday.

Applegate broke down in tears as she recalled a doctor recently saying, "Congratulations. You don't have MS," NBC News reported. "You don't get misdiagnosed and then all of a sudden I'm better," she said to co-host Jamie-Lynn Sigler, according to NBC News. "I'm back at square one, that I don't know what's going on with me."

She said she had "every symptom of someone with MS," including weakness, pain and difficulty walking, USA Today reported. She said it "hurts to stand up" and that she is "sleeping all the time," according to USA Today. Her medical team will work to find the underlying cause of her symptoms, NBC News reported.

In the episode's second part, neurologist Marwa Kaisey said misdiagnosis is "fairly common" because "we don't have one, single test for MS," USA Today reported. Kaisey said a study she ran of new MS patients found that almost one in five of them did not actually have the disease, according to USA Today.

Applegate said she felt she had "let everybody down" after she and Sigler became "poster children for MS," USA Today reported. Sigler was diagnosed with multiple sclerosis roughly 25 years ago, NBC News reported. Sigler said Applegate did nothing wrong and "didn't mislead anyone," according to USA Today.

Applegate announced her diagnosis in August 2021, USA Today reported. She received a standing ovation at the 2024 Emmy Awards, appearing onstage with a cane, and she spent months in the hospital this year, NBC News reported. She is best known for "Married ... with Children" and "Dead to Me" and won an Emmy in 2003 for a guest role on "Friends," according to NBC News.

What we know: Applegate says doctors have ruled out MS but her symptoms continue.
What we don't: What is causing her symptoms.