Jayme Deerwester

USA TODAY

Jamie-Lynn Sigler, who played the emotionally conflicted daughter of mobster Tony Soprano on the Emmy-winning HBO drama, has gone public with her struggle with her nearly 15-year battle with multiple sclerosis.

She shared her story with People in this week's issue, due on newsstands Friday.

The actress, now 34, says she was diagnosed with the autoimmune disorder at 20, when she was still on The Sopranos and experiencing feelings of tingliness and heaviness in her legs. She says she kept her illness a secret on the set, telling the magazine that, "Sometimes all I needed was like five or 10 minutes to sit and recharge but I wouldn't ask, because I didn't want them to be suspicious."

She told the magazine that she had been symptom-free for several years but it caught up to her in the last decade. "I can't walk for a long period of time without resting. I cannot run. No superhero roles for me," she explained. "When I walk, I have to think about every single step, which is annoying and frustrating."

Aside from confiding in a few trusted colleagues such as her TV father, James Gandolfini, she kept her secret close to the vest for years. "I wasn't ready until now," Sigler told People. "You'd think that after all these years, somebody would be settled with something like this, but it's still hard to accept."

Sigler is in a better place today, taking a twice-daily dosage of Tecfidera, which stabilizes her symptoms. And she has a happy home life with her new husband, baseball player Cutter Dykstra (the son of Mets and Phillies great Lenny Dykstra) and their son, Beau, who was born in 2013.

"Things are manageable now," she told the magazine. "It takes a fighting attitude to deal with all this. This disease can absolutely take over your life if you let it."

Multiple sclerosis is named for the sclere, or lesions, that appear on the white matter of the brain and spinal cord in patients and is characterized by the fraying of the myelin sheath, or insulating covers for those nerve cells. Like Sigler, most patients are diagnosed between the ages of 20-50. The disease is twice as common in women as it is in men.

The NBC drama The West Wing gave the MS community a national platform when the disease was made a major story line for President Josiah Bartlet (Martin Sheen). He was diagnosed before the show began and was treated by his doctor wife to avoid leaving a paper trail. Eventually, he began having attacks while in office and went public with his illness near the end of the second season (2001).