It’s easy to shrug off a bit of numbness in your hand or losing your footing here and there. Unfortunately, as actor Christina Applegate learned in 2021, those usually not-so-worrisome symptoms can sometimes be a sign of something more serious. Applegate was diagnosed with multiple sclerosis (MS) during filming of the third—and what was already to be the final season—of the Netflix show Dead to Me .

Though MS was first defined by a neurologist in 1868 , the medical community still doesn’t know what causes it. The disease impacts the central nervous system—the brain, spinal cord, and optic nerves. Think of it as the wiring that runs through bodies and drives movement, thought, mood and, basically, everything a person thinks or does throughout their day.

Those hits on the nervous system can lead to symptoms both short-term and long-lasting. Each attack on the nervous system leaves behind lesions that, together, tell the story of MS in a person’s body. One isolated symptom doesn’t tell the story of MS.

It takes multiple lesions to lead to a diagnosis. Michelle Tolson understands how overwhelming the words “You have multiple sclerosis” can be. A dance educator and former Rockette at Radio City Music Hall, Tolson was diagnosed in 2014 when she was 40.

She had a blurry left eye, so she decided to see her doctor. “I thought I had to up my prescription for my reading glasses. It was kind of weird.

I equate it to a disco ball glare,” Tolson says. Tolson’s docto.