Laptops put all of the important hardware for running a computer into a small area. Because everything is so compact, laptops have a tendency to get hot. To keep your processor and other critical components cool, your laptop has multiple fans. Several situations can arise that would cause your fans to make noise.
Some laptop fans are simply built in a way that makes them loud when they operate. HP laptop fans are notorious for being loud when the computer heats up. Several brands of fans might operate louder than others, and there is little that can be done to make them quieter.
Laptop fans can become dusty, which stresses the components and can make the fan louder. You can clean the laptop fan. To do so, you can spray the fans with compressed air, which might remove some dust. To completely clean the fan, you will have to remove it and clean it with either compressed air or a cleaning product approved for use on electronics.
After some time, computer parts might wear out and break. If your computer is overheating, the fans might have to over-clock to compensate. If one fan breaks, the other fan will have to work harder. A long list of scenarios of broken or worn out components might cause your computer to overheat or your fans to run loud. You can try to replace the fan or run a hardware diagnostic to fix the problem.