What happens if I don't renew my TIE residency card in Spain?

After five years of temporary residency in Spain you can apply for long-term residency. But what happens if you don't? How about if you already have a long-term residency card and don't renew it after five years?

What happens if I don't renew my TIE residency card in Spain?
After five years of temporary residency in Spain you can apply for long-term residency. But what happens if you don't? How about if you already have a long-term residency card and don't renew it after five years?