How long should fuses last?

Could you please elaborate on the expected lifespan of fuses? It's a crucial aspect of electrical safety, and I'm curious to know if there's a general guideline or if it varies based on factors like the type of fuse, the electrical load it's handling, and the environment in which it's installed. Additionally, what are the signs that indicate a fuse might be nearing the end of its lifespan, and what should one do when a fuse fails to protect the circuit from an overload?