"Shocking" Shock Absorber Facts

Bouncing down the road one day it occurs to you that things are just not what they should be. The road you are riding on is as smooth as glass, yet your car is jostling up and down like nobody's business. You enter an upcoming curve in the road and quickly learn that the control you had over your car was lost just moments before. Suddenly, the vehicle careens off the road, goes down through a ditch and up an embankment before coming to rest against a fence adjacent to Chuck and Eddie's. You are in luck: you aren't dead and your car is at the junk yard.
Yes this story is ridiculous, exceedingly so. All joking aside, your shock absorbers [or struts in the case of some cars] plays a vital part in your vehicle's suspension system. When certain signs of wear and tear become apparent, you must replace your shocks or otherwise you can put yourself in danger and/or damage your car.

A shock absorber works by damping the compression and extension of the vehicle's suspension springs to prevent ongoing movement. Shocks work to diminish road impact, prevent excessive bounce back, reduce sway, and improve general road handling. When your shocks are functioning properly your vehicle grips to the road whether you are braking, negotiating a curve in the road, driving on uneven roads, or experiencing powerful side winds. When worn out, shocks can play a part in you losing control of your car putting you and everyone else in harm's way.
How often should you replace your shocks? One manufacturer suggests no less than once every 50,000 miles, but that depends on whether you frequently drive on coarse roads [in this case it will need to occur sooner] or it could even be much later if you do mostly local driving, the roads are well maintained, etc.
There is a simple test you can perform on your car to establish whether your shocks need replacing. It isn't absolute, therefore you may want to take your vehicle to a garage to make certain:
Take hold of a corner of your vehicle's bumper.
Press down on the bumper with all of your strength and then let go.
Your shocks are probably okay if the bumper drops down and returns in place without rebounding again. Slight movement is okay, but if it continually moves, then that particular shock is no longer effective. Duplicate the test on the remaining three corners of your vehicle.
Other telltale signs of shock wear can be observed through leakage [although a leak is not always indicative of wear] and by observing tire wear patterns. Finally, if you are simply experiencing motion sickness every time you go for a ride, then that can be the best indicator that your shocks or struts need replacing. No kidding here!