Hastings mother Sharon Payne said there was no hesitation and has no regret from giving a kidney to son Stephen eight years ago.
He suffers a rare bone disease that came with renal failure.
"We knew what was going to happen, it was just a matter of when. When he was about 17 his kidneys failed. Both my husband and I were prepared to give him our kidney but I was the better match," she said.
Dialysis had not agreed with him.
"I would get out of bed just to go the dialysis and then return home to bed," he said. "I got down to 40kg because if I ate anything I would throw it straight back up."