Hyland, 21, told the magazine that her father donated one of his kidneys to her.
"You know that family is going to be there for you no matter what. My dad gave me a freakin' kidney!" Hyland told Seventeen. "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."
Kidney dysplasia, also known as multicystic dysplastic kidney, occurs when there are problems with the kidneys as they develop, and cysts -- which are filled with fluid -- grow where normal kidney tissue is supposed to be, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).
Usually, just one kidney is affected by kidney dysplasia; if this is the case, someone with kidney dysplasia may experience few, if any, problems from the condition. But if kidney dysplasia affects both kidneys, then the person may need to undergo dialysis -- where a machine filters waste from the body in place of the kidneys -- or have a kidney transplant.
Today, kidney dysplasia can be diagnosed while the baby is still in the womb. After birth, a renal and bladder ultrasound is then conducted to confirm the condition; on the ultrasound, a kidney affected by kidney dysplasia will just appear as cysts, according to the Children's Hospital of Philadelphia.
The condition occurs about once out of every 4,300 live births, according to Children's Hospital Boston. It's more common in white people, but is about equally common in males and females.
There is no "one way" to treat kidney dysplasia, according to Children's Hospital Boston. Most doctors recommend monitoring the affected kidney, because -- while rare -- high blood pressure or tumors can develop. Some parents may opt for their child to undergo surgery, called a nephrectomy, to remove the kidney.
Children's Hospital Boston reports:
The long-term outlook for a child with a complete or partial nephrectomy is very good, since most people have a second, normally functioning kidney that can adequately meet the body's needs.
To see what other celebrities have undergone organ transplants in the past, click through the slideshow: