There are a number of reasons your camshaft sensor might break down: grime and oil in the engine, water damage, bad wiring, and overheating can all cause a camshaft sensor to go bad.
The biggest thing to do to avoid this is to take care of your car. Make sure you’re cleaning your engine semi-regularly, at least once a year, to prevent grime buildup. You can also ask your mechanic to check your camshaft sensor when you get your car serviced to see if there are any issues.