Recently I have noticed that the fan in my laptop has started making more noise than customary.

It could be as crude as being a little dusty. Blow into the exhaust port to hand the fan, or give it a blast of Air Duster. It might as well just be that the computer is getting old and the fan is a little louder as a result. If it really starts to bug you, take it location, merely it's fine to keep using...the real danger is if the fan isn't working at all lol