And after she was diagnosed at age 20 with multiple sclerosis (an autoimmune disease, also known as MS, that impacts the central nervous system), Sigler was able to keep her condition a secret for several years until symptoms started to present themselves.
“I was still able to hide it really well,” she tells PEOPLE in this week’s issue. “I didn’t really need help necessarily, it was more like some pain and feeling uncomfortable but I could easily hide it.”
• For more of Sigler’s revealing interview, including exclusive photographs from her wedding album, pick up this week’s issue of PEOPLE, on newsstands Friday
The actress eventually told a few cast members, including Gandolfini, because “they were very much like family to me,” she says. “You can only handle so much by yourself. So the people I felt safest with, I confided in.”
Gandolfini, who died from a heart attack in 2013 “was very aware and protective in general, but especially after I told him,” Sigler adds. “He was really awesome about it.”
The support meant everything to Sigler, 34, who now has weakness in her right side and can’t walk for long periods of time without resting. “Sometimes it makes you feel better to know that somebody else knows,” she says. “And if you are having a hard day, if you’re a little tired, even a pat on the back can make all the difference.”
• For more on living with MS and to contribute to the fight against the disease, visit The National Multiple Sclerosis Society
The actress says she wanted to reveal her diagnosis now in hopes of helping others: “I’m never going to know why I have this until I live my truth,” she says. “But it doesn’t define me.”