Tie rods on your vehicle usually just go bad overtime naturally due to wear and tear.
When you turn your steering wheel back and forth your tie rods are being used all the time and that constant turning of your steering wheel causes the tie rods to wear out and become loose and then need replaced.
If the joint on the tie rods comes completely apart then you can loose your steering control and loose control of the vehicle.
So if you have a loose steering wheel or bad tie rods you should get them replaced before driving the vehicle any further.
Other things can cause tie rods to go bad as well such as poor driving conditions and hazards such as poor road conditions, car accidents, and potholes.
Tie rods should easily last 100,000 to 300,000 miles or more depending on the driving conditions but if you're getting loose steering or your wheels are getting out of alignment then it could be time to replace the tie rods regardless of miles driven.