American swimmer Cody Miller won a bronze medal in the 100-meter breaststroke on Sunday, overcoming a rib condition that he has had since childhood.

So happy, he told NBC after winning. I have been dreaming about this since I was a little kid, and you never really think its going to happen until it happens.

Miller clocked in at 58.87 seconds, breaking the U.S. record for the event. The 24-year-old has a medical condition called pectus excavatum , which makes his chest appear caved in. In severe cases, a persons heart or lungs can become impaired.

After his diagnosis, Miller began swimming to monitor his heart and breathing, according to the swimming website Swim Swam. His swimming career took him to Indiana University, the U.S. National Junior Team, and eventually, the Olympic games .

Britains Adam Peaty set a new world record in the 100-meter breaststroke to take home gold.

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