Christina Applegate, Selma Blair, Jamie-Lynn Sigler, Jack Osbourne and many other celebrities have opened up about dealing with multiple sclerosis, an autoimmune disease. Applegate revealed in August 2021 that she was diagnosed with the condition. "Hi friends. A few months ago, I was diagnosed with MS," the Married ... With Children alum wrote via X at the time. "It's been a strange journey. But I have been so supported by people that I know who also have this condition. It's been a tough road. But as we all know, the road keeps going. Unless some a**hole blocks it." Former Try Guys YouTuber Ned Fulmer revealed his diagnosis in November 2025. "I was diagnosed in 2013, and it started just by numbness and tingling in my hands that spread to my arms and chest and back," he exclusively told Us before announcing his diagnosis publicly via YouTube. Keep scrolling to see other stars who have been diagnosed with MS: