Christina Applegate is continuing to search for answers in her ongoing health battle.
During the Nov. 3 episode of her "MeSsy" podcast, the Emmy-winning actress and podcaster revealed she's undergoing medical testing for new conditions following her misdiagnosis of multiple sclerosis.
"We're going into square one, just doing some testing and going one by one of kind of the sister diseases to MS," Applegate, 54, told guest Jack Osbourne, who has MS.
Applegate revealed in October that she does not have multiple sclerosis, despite being diagnosed with the autoimmune disease in 2021. Her doctor recently told her she had been misdiagnosed.
The "Married... with Children" alum does not yet have a new diagnosis. She previously explained that she still has
the same symptoms, including fatigue and pain, but no longer has an explanation for them.
Applegate detailed some of the medical tests she's been taking as she and her doctors reevaluate her health struggles.
"You've got RA [rheumatoid arthritis], and you've got lupus and Lyme disease and all these things that kind of can mimic MS," Applegate said. "So, now I'm being tested for all that stuff, slowly but surely."
Rheumatoid arthritis is an autoimmune condition that "affects the lining of the joints and eats away at the bone under them," according to Mayo Clinic. It's often characterized by bouts of inflammation, which consist of pain, swelling and irritation in someone's joints.
Lupus, also an autoimmune condition, can cause inflammation that affects a person's joints, skin, kidneys, blood cells, brain, heart and lungs, per Mayo Clinic. It can be difficult to diagnose because symptoms can appear similar to other illnesses.
Lyme disease is an illness that occurs when someone is infected with borrelia bacteria, according to Mayo Clinic. The bacteria is often transmitted from a tick bite. If not treated, the disease can worsen, with symptoms ranging from neck pain or stiffness, muscle weakness in the face, and back and hip pain to numbness or weakness in the hands and feet.
Applegate has been open about her health over the past five years since receiving her original MS diagnosis. In 2024, she launched the podcast with actress Jamie-Lynn Sigler, who has been diagnosed with MS.
The pair plan to continue their show despite Applegate's misdiagnosis. On their Oct. 27 episode, Sigler said the podcast is "about the messiness of life in general" and was not "meant to be solely MS-focused," even though this was the initial "reason for us speaking candidly with each other."
This article originally appeared on USA TODAY: Christina Applegate details new medical testing after MS misdiagnosis
