If your unit is low on freon it will cause the coils to freeze up. If you have insufficient air flow that will also cause them to freeze. If your air filters are dirty long enough it will trickle to the coil and cause it to get dirty. Preventing them from operating properly. Regular monthly maintenance can prevent this from happening. Also check to make sure your refrigerant lines are insulated.
If left to long Yes the problem can become quite serious and cost more money and time to repair then just simply doing regular maintenance on the unit itself.

At least once a year to maintain a license to operate.