What are some medical conditions which may require a living relative to donate to keep their loved one alive?

Hi I am working on developing a short script into a feature and I'm beginning my research, I was just wondering what some of the health issues are which would require a middle aged man to get in touch with a relative he fell out of contact with long ago in order to get better??



And also (not compulsory) how would you react if someone from your past got in contact with you the only purpose for them to get better??



Thanks in advance :)What are some medical conditions which may require a living relative to donate to keep their loved one alive?
Anything requiring organ or tissue donation requiring close matching. Kidney and bone marrow are common. Lung and liver transplants, less so.



I like to think I'd be open to at least considering a donation to someone I knew long ago who needed my help to get well. I'd have little problem donating bone marrow or a hunk of liver, since those will regenerate. Giving up a lung or kidney is more serious and will impact me for the rest of my life. I might even consider it if they'd done me wrong; illness is a great humbler and levels the playing field.