Elizabeth Marks earned her fourth gold medal in swimming in the 100-meter freestyle Wednesday at the Invictus Games at Disney World.
She gave it back to Prince Harry, with the intention that he take it to Papworth Hospital near London.
Elizabeth Marks collapsed with a serious lung condition in 2014 on the eve of the first Invictus Games and was put into a medically induced coma.
She was treated in London by a team from Papworth, who put her on life support for 10 days after she suddenly became ill.
She said: “They absolutely saved my life and I can’t thank the UK enough for having that kind of medical support and taking such good care of me.
“So I gave Prince Harry one of my medals and hope it will find its way back to Papworth.”
Elizabeth Marks, who has won every swimming event she entered at this year’s games in Orlando, decided to give her 100m freestyle gold to the hospital as it had been touched by the Prince.
Holding back tears, she said of the NHS staff who treated her: “Thank you, I’ll never be able to repay you, but what you’re doing is wonderful.”
The combat medic was left with no sensation in her left leg after suffering a serious hip injury in 2010, but has returned to fitness and still serves in the military.
She described it as “an honour” to compete in the games alongside the other servicemen and women taking part.
Elizabeth Marks, who joined the US Army at 17, added: “I was nervous because of what had happened last time but I was eager to perform and show my team and show the other countries how much I love their support.
“When I came out of my coma to see all the pictures of them supporting me while I was there, without even knowing I was in that state, made me cry like a baby so it was a chance to give something back.”
Prince Harry launched Invictus in 2014 as a means of using sport to support the rehabilitation and recovery of injured soldiers, and staged the inaugural games in London.