Lisa Kudrow felt like a 'mountain of a woman' next to 'Friends' co-star Jennifer Aniston

Lisa Kudrow is opening up about her struggles with her body image while she was on "Friends." 

The 55-year-old actress, who played Phoebe Buffay on the beloved sitcom from 1994 to 2004, revealed that she continually compared her appearance and weight to co-stars Jennifer Aniston and Courteney Cox.

"You see yourself on TV and it’s that 'Oh my God, I’m just a mountain of a girl,'" she said on the "WTF With Marc Maron" podcast Monday. "I’m already bigger than Courteney and Jennifer, like, my bones feel bigger."

She continued: "I just felt like this mountain of a woman next to them."

Related: Why Lisa Kudrow doesn't watch 'Friends' reruns

The "Booksmart" star said she pressured herself to make some unhealthy choices to regulate her weight, which frustratingly led to compliments instead of concern. 

"Unfortunately for a woman, if you’re underweight, you look good and that’s all I ever got," Kudrow revealed. "When I was too thin I was sick all the time, a cold, sinus infection, I was always sick."

Kudrow said she still struggles with her body image nowadays but noted that she's coming to terms with aging and accepting her physique. 

"I have a whole battle all the time," Kudrow said. "I end up with, 'So what? So, all right. You’re older. That’s a good thing. Why is that a bad thing?'"

Kudrow recently told "Entertainment Tonight" that she can't bring herself to watch reruns of the series, which turns 25 this year.

"I don't watch it if it's on," Kudrow shared. "I might not like myself (on the show), so I'd rather not risk that."

Contributing: Maeve McDermott