
Christina Applegate tests for Lyme disease and lupus after misdiagnosis
November 3, 2026, 12:07 p.m. ET
Christina Applegate continues to search for answers to her ongoing health battle.
During the Nov. 3 episode of her podcast “MeSsy,” the Emmy-winning actress and podcaster revealed that she was undergoing medical testing for new conditions following her misdiagnosis of multiple sclerosis.
“We’re going to square one, just doing some tests and looking at MS’s sister diseases one by one,” Applegate, 54, told guest Jack Osbourne, who has MS.
Applegate revealed in October that she did not have multiple sclerosis, although she was diagnosed with the autoimmune disease in 2021. Her doctor recently told her she had been misdiagnosed.

The “Married… With Children” alum doesn’t have a new diagnosis yet. She had previously explained that she still had the same symptoms, including fatigue and pain, but that she no longer had an explanation for them.
Applegate detailed some of the medical tests she’s had as she and her doctors re-evaluate her health concerns.
“You have RA (rheumatoid arthritis), lupus, Lyme disease and all these things that can mimic MS,” Applegate said. “So now I’m being tested for all of this, slowly but surely.”

Rheumatoid arthritis is an autoimmune disease that “affects the lining of the joints and eats away the bones underneath,” according to the Mayo Clinic. It is often characterized by bouts of inflammation, which consist of pain, swelling, and irritation in a person’s joints.
Lupus, also an autoimmune disease, can cause inflammation that affects the joints, skin, kidneys, blood cells, brain, heart and lungs, according to the Mayo Clinic. It can be difficult to diagnose because the symptoms can resemble those of other illnesses.
Lyme disease is an illness that occurs when a person is infected with the borrelia bacteria, according to the Mayo Clinic. The bacteria is often transmitted by a tick bite. If left untreated, the condition can worsen, with symptoms ranging from neck pain or stiffness, facial muscle weakness, and back and hip pain, to numbness or weakness in the hands and feet.
Applegate has spoken openly about her health over the past five years, since she was first diagnosed with MS. In 2024, she launched the podcast with actress Jamie-Lynn Sigler, who was diagnosed with MS.
The duo plans to continue their show despite Applegate’s misdiagnosis. In their October 27 episode, Sigler said the podcast was “about the messiness of life in general” and was not “intended to be just MS-focused,” although that was the “original reason we were talking candidly with each other.”
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