"If I had another spare kidney, I'd do it again," Tracey tells the BBC's Victoria Derbyshire programme.
She is what is known as an "altruistic donor" - someone willing to give away an organ to potentially help save the life of a complete stranger.
A microbiologist in the NHS, and the daughter of two nurses, she has spent her life learning about the importance of healthcare from a professional standpoint.
But she has also been keen to make a difference on a personal level. Continue reading