If you hit a bump in the road and your vehicle just keeps bouncing up and down for a lot longer time than it used to, you may have bad struts and shocks. They're the things that help to keep your vehicle's wheels and tires planted to the road surface.
But they don't last forever. With care and depending on where and how you drive, shocks and struts should be replaced at intervals ranging from 50,000 miles/80,000 km to 100,000 miles/160,000 km. If you drive on bumpy roads with a lot of potholes, that interval will likely be shorter. Rough surfaces can take their toll.
But how do you know if your shocks and struts are doing their job properly? The best way is to have your vehicle checked by a technician. He or she can inspect the shock absorbers and struts for leaks, corrosion and damage. Mounts and bushings can also go bad, and they should be evaluated as well. A thorough examination by a technician will also include looking at other suspension parts. Some may contribute to making your vehicle behave the same way if they're broken, corroded, worn or bent.
If you need new shocks and struts, your service advisor will make sure that you get those that meet manufacturer's specifications. That's important because they want to make sure you're getting the handling and performance engineers designed your vehicle to have.