What defines "healthy"?

A relatively young friend (in his 40-something) told me he's going to have a few heart stents installed. Not one, but a few.

He did exercises regularly and is capable of weightlifting maybe more than I can.

Do heart stents mean unhealthiness?

It seems beyond the question. How can you call yourself healthy if you need stents?

That brings up an interesting question. What separated healthy from unhealthy? If someone hurt his arm and needed a metal joint planted, will you call him "unhealthy" after he fully recovers?

What if he fully recovers after having heart stents installed?

Does unhealthy mean one still has risk after recovery? What kind of risk counts? Who (especially ones in the middle age) dares to claim a life without such risk?

That's why we always put ourselves in some mental shadow. How about keeping ourselves in a recovered status quo and call ourselves healthy?