"Modern Family" star Sarah Hyland has kidney transplant

(CBS/AP) "Modern Family" star Sarah Hyland has had a kidney transplant after a lifetime of pain and fatigue.

The 21-year-old actress, who plays big-eyed teenager Haley Dunphy on the hit ABC comedy, told "Good Morning America" that she had the surgery in April.

At age nine, she was diagnosed with abnormal kidney development.

The condition often left her exhausted or in pain. But as her health grew worse, she began seeking an organ donor. Her father, actor Edward James Hyland, was a match.

She says she tells her dad, "It's weird - I've got your kidney in me."

Hyland plans to spend the show's summer hiatus recovering from her surgery.

Her secret struggle is also reported in the current issue of Seventeen.

"You know that family is going to be there for you no matter what," she told the magazine. "My dad gave me a freakin' kidney! But it's also the families that you create outside of your family. And you really find out what kind of people you're friends with. It was just amazing, and it really opened my eyes to see who's there for me and who's not."

Highland said her boyfriend, fellow actor Matt Prokop, has been a big help.

"He helps me with my medication and takes me to doctor appointments and all the stuff that I need to do to take care of myself," she said. "Any other 21-year-old guy would not be there, I guarantee it."