Ditch your current razor if it is dull or rusty.
Let’s start with rust: razor rust and skin do not mix well! When a razor has little brownish-orange spots on the metal, that’s rust and it means toss the razor. Yes, even if you really, really need to shave and you don’t have another one around. That’s because rusty razors can cut and infect skin really badly.
Now, onto dulling. After several uses, razor blades dull. When this happens, they don’t cut the hair effectively, and if you push down harder on the skin to try to make the dull razor work better, this will only result in tiny nicks and scrapes along the skin. It can be hard to tell when a razor has dulled, but if you’re shaving and hair isn’t coming off, that’s a clue. Sometimes soap or shaving cream get stuck behind the blades, so make sure to rinse your razor frequently during your shave. But if the hair still isn’t coming off nicely or takes multiple tries, dullness is probably your issue. Time to toss that razor.