If your car is more than a few years old, then it might be time to start thinking about replacing the water pump. The water pump is responsible for circulating coolant throughout the engine, and over time, it can become less effective at doing its job. Replacing the water pump is not a particularly difficult or expensive repair, but it is one that should be left to a professional mechanic.
If you are experiencing any issues with your car's cooling system, such as overheating or leaks, then it is worth taking it in to have the water pump checked out. In most cases, if the water pump needs to be replaced, the timing belt will also need to be replaced (as they are usually located together). This can be a more costly repair, but it is still worth getting done sooner rather than later to avoid further damage to your engine.