For a moment, imagine that you're 15 years old again. Your worries are few, and your toughest challenges include earning good grades, keeping up with the latest fashion trends and finding a date for the school dance.

All right, it might have been more complicated than that. But teenagers aren't expected to make important decisions that early in life, right? Perhaps for some, but that wasn't Cindy Nuño's story.

It all started when she was about three years old. While on a trip visiting relatives in Mexico, Cindy was rushed to the emergency room at a nearby hospital — her defective right kidney needed to be removed immediately. Although the surgery went well, all the work now was shifted to her left kidney, which also hadn't worked properly since birth. From that point on and all throughout childhood, Cindy battled severe infections and endured many operations to maintain normal kidney functions. (The kidney is responsible for cleaning the blood by filtering our extra water and wastes. It also produces hormones that keep bones strong and healthy.)

Now fast-forward to 1990. Her weak left kidney couldn't handle the demands of her 15-year-old body anymore. Cindy had now reached a critical point and needed to make an important decision: undergo regular dialysis, a treatment that uses a machine to filter the blood, or have a kidney transplantation.

"When you're young and are faced with a difficult situation, you're not sure what to do," says Cindy. "At that age, you think that nothing bad can happen to you." After talking with her family, physician and other members from Children's Memorial's kidney transplant team , it was decided she'd undergo transplantation.

The kidney transplant program is staffed by a multidisciplinary team of health professionals, including nephrologists, transplant surgeons, and dialysis nurses and technicians, among other.

The program offers both living related and cadaver kidney transplantation, which allows patients to live without dialysis and have a fairly normal life. Children's Memorial currently performs about 20 kidney transplants each year and has performed more than 390 transplants since the program began in 1962.

Anyone who has ever needed a kidney (or any other organ) knows that it could take months — perhaps years — for a compatible donor organ to be found. In some cases, however, a relative may provide a donor kidney if the blood and tissue types match.

Fortunately, Mary Elsy Nuño, Cindy's mother, had a kidney to spare — and it was a perfect match! For Cindy, the outlook was good; living-relative kidney transplantation outcomes are quite promising because of the nearly 90 percent success rate. This means that the chance of Cindy rejecting her new kidney was remote.

"As a parent, you'd do anything to save your child's life without thinking twice," says Mary Elsy through an interpreter. "Giving my daughter one of my kidneys was one of the greatest gifts I could ever give."

After the surgery, both came through with flying colors. However, it changed the course of Cindy's life forever. "Many things changed for me, good and bad. But the fact that my health would improve outweighed all the rest," Cindy explains.

The most drastic change was the twice daily ritual of taking immunosuppresants and other drugs so she wouldn't reject the new organ. "When you're 15, it's difficult to remember to take all of your medications at regular intervals for the rest of your life," she says. "It all comes down to this — you either take your medication and live or don't take it and, well, you can guess the rest." It's a simple philosophy and she sticks to it

But there were other adjustments, too, such as her new "look."

Most transplant patients experience side effects from the immunosuppressants. They may gain weight or develop acne or facial hair. "When you're 15 and in high school, your looks are pretty important. So it was very strange to look into the mirror and see someone else." she says. "It's been six years since the surgery, and I still expect to see the 'old' me."

Another change the new kidney brought was a surge of energy. Cindy recalls attempts to run the mile in gym class. "I just couldn't run the entire thing and would always end up walking because I got tired." The summer after her surgery, however, Cindy challenged herself and went to the school track. She ran the mile without stopping once.

Six years have passed, and we again find Cindy in high school. This time, Cindy is the teacher and not the student; she's a spirited 23-year-old Spanish teacher. An interesting sidebar to her story is that Cindy met a student at the school who also had a kidney transplant at Children's Memorial. "It's a small world," she chuckles at the coincidence of meeting someone who shared many of the same experiences.

Cindy's experience has made her an enthusiastic advocate for organ donation. She even publicly spoke about the importance of organ donation while attending college at Illinois State University where she earned her teaching degree. Cindy also encourages all of her family members and friends to sign their driver's license and tell their loved ones that they have decided to be donors.

"It's an important decision," she says. "It's also a way you can help someone who doesn't have any other options."