Lisa Kudrow felt like a ''mountain'' next to her 'Friends' co-stars.

The 55-year-old actress has opened up about her problems with body image and she admitted she felt uncomfortable on the set of the iconic sitcom because she was so much taller than Jennifer Aniston and Courteney Cox.

Speaking on Marc Maron's 'WTF' podcast, she said: ''You see yourself on TV and it's that, 'Oh, my god, I'm just a mountain of a girl.

''I'm already bigger than Courteney and Jennifer - bigger, like my bones feel bigger. I just felt like this mountain of a woman next to them.''

Lisa added she ''always'' made herself ''sick'' by staying ''underweight'' for a while.

She explained: ''Unfortunately for a woman, if you're underweight, you look good. And that's all I ever got.

''When I was too thin, I was sick all the time. A cold, sinus infection... I was always sick.'' Now however, the star faces ''a whole battle'' to feel more at peace with her own body, and she insisted she is in a place where she can accept growing older.

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

Meanwhile, Lisa - who added she mainly stays in touch with Jennifer and Courteney from the cast - recently revealed she doesn't like watching back old episodes of 'Friends' in case she doesn't like her character Phoebe Buffay.

She previously admitted: ''I don't watch it if it's on. I might not like myself [on the show], so I'd rather not risk that.''

The 'Booksmart' star also reminisced about the ''thrilling'' pilot episode, which aired on NBC in September 1994, and how young and new to the game she and her co-stars - including Courteney (Monica Geller), Jennifer (Rachel Green), Matt LeBlanc (Joey Tribbiani), Matthew Perry (Chandler Bing) and David Schwimmer (Ross Geller) - were.

She added to 'Entertainment Tonight': ''The pilot. Just how thrilling that was. We were like little puppy dogs, just climbing all over each other and playing and playing games. It was fun.''