Ed Helms had open heart surgery as a teenager.

The 'Vacation' star has revealed he suffered from a severe heart murmur as a young boy and had to undergo the serious operation to correct the problem.

When asked for 25 surprising facts about himself, he told Us Weekly magazine: ''I have a nice, long scar on my chest from open heart surgery when I was 14.''

The 41-year-old actor previously insisted everything was ''fine'' following the surgery.

He said at the time: ''I had open-heart surgery [to repair a murmur] when I was in the seventh grade.

''Everything is fine now. I have a 10-in. zipper scar right down my sternum.''

It is not the first time Ed has felt uneasy in a hospital as he also revealed he nearly suffered a panic attack whilst in a magnetic resonance imaging (MRI) machine.

He shared: ''I almost had a panic attack inside an MRI machine but managed to keep it together.''

Despite the setback, he was a keen sportsman at school, something which has continued on with him into later life.

He said: ''My shoulders are very loose from competitive swimming in high school and college ...

''I will run for hours in a game of soccer or basketball, but I can't stand jogging.''