Unpaid credit card queastion?

Due to illness and having to give up a good paying job. I don't see me ever being able to pay off some credit cards ever. its been 5 years on some now. Is there a time limatation where this goes off your credit rating ? The interest has added up and just keeps going up.At some point do they give up and count this as a loss? Or does this just continue all your life untill you pay it off? if so I'm in major trouble. I have not and will not regain my health to the point of being in a point in my life where I can get these paid off.