ASTORIA, Ore. -- A teenager's only kidney is slowly wearing out, and soon he may need a new one to live.

Zach Walker got his first donated kidney from his grandfather 14 years ago, and now his mother said that when her son needs a new kidney, she's ready to donate one of hers.

In 1994, E. coli poisoning destroyed Walker's kidneys when he was just 2 years old.

Soon after his illness, he received a kidney from his grandpa, and while living with a transplant can be challenging, Walker said he feels lucky to be living a quality life.

For Walker, life has had its ups and downs, but he said living with only one kidney hasn't really held him back except for some sports.

"Football is a big one for me. I've always wanted to skydive, but they tell me I can't do it," Walker said.

When E. coli destroyed his kidneys, extensive testing showed his grandfather was a match and the child's body wouldn't reject it.

Zach's grandfather, Garry Phelan, said the decision wasn't difficult at all -- "not with a grandchild it wasn't."

In fact, he would do it again if he could.

"It's really been no difficulty for me. I even got a little pride out of doing it," Phelan said.

While the kidney has performed better than expected, it's now wearing out.

"I feel weaker. I don't have as much energy as I had," Zach Walker said.

And while he can still play and work outdoors, he will need a new kidney soon.

This time his mother, Jacque, will donate one of hers.

"I worry about him a lot," Jacque Walker said.

But she's more worried about not being there to help her son if he gets sick after the operation than she is about losing her kidney.

"I mean, I'm nervous about the surgery, but I'm more nervous about not being there for him when he wakes up," Jacque Walker said.

If the new transplant goes well, the kidney could last for decades, giving Zach Walker the long and healthy life on which he might have otherwise missed out.

"I've just kind of accepted it. I'm kind of lucky to be alive. You know? I could've easily died like anybody else," Zach Walker said.

If he didn't have a kidney donor, he might have had to undergo 12 hours a day of kidney dialysis.

Fortunately, the family has good insurance to help pay for the transplant operations.

Mother To Provide Teenage Son With New Kidney