Claire Foy opens up about having ‘extremely painful’ juvenile arthritis as a teen: 'I was on crutches'

Claire Foy is opening up about some of the challenges she faced during her childhood.

In a new interview with WSJ — for its February issue — published on Wednesday, the "First Man" star revealed that she struggled with academics and anxiety, as well as had juvenile arthritis growing up.

"Feeling stupid is not a nice thing. I wasn’t really good at anything," Foy recalled about her studies, adding she "was relatively good at home economics, at making cakes" and was "quite sporty.”

“But I had juvenile arthritis from the ages of 12 to 15, so I was on crutches," she continued. "[The arthritis] was extremely painful."

The 34-year-old actress went on to share that anxiety was also a part of her life "at that age." However, it wasn't until she was in her mid-20s that she realized "that was what it was." Fast-forward to today, Foy says she still struggles with mental health.

"It’s not as bad at it was, but that’s through a lot of work, doing things that I never thought I would do,” she explained, noting that she's had therapy and uses a meditation app called Calm.

"I know that I need to catch myself early in a process of overthinking," Foy added. "It’s always about questioning myself. Even though I have had a thought a million times...it will always be something I need to think about another million times that day. It will be like, ‘Shall I go for a walk today?’ or [about] massive life decisions.”

When it comes to choosing which roles to take on though, the Emmy winner doesn't stress too much.

"I don’t fanny around," "The Crown" alum told the news outlet. "My stomach normally tells me whether it’s something bad or good.”