Whining noise is due to worn out brake pads, metal rubbing against metal, you are already damaging your rotors.
Get a brake job now and you might be able to save your rotors and only need resurfacing. If you wait longer, you'll need to replace the rotors too.
Of course you should worry if a vehicle is making a noise it shouldn't, and continuing to drive it in that state will obviously be causing more damage.
You should only have concern if stopping the vehicle in a safe and reliable manner is important to you. Otherwise feel free to go about smashing into things.
Yes it should be of concern check Rotors Axles Bearings etc or just take it to a good mom & pop auto shop.
You most certainly should be concerned. Go to a reputable shop asap.
The next time you drive it should be to a mechanic.
warped rotors or pin missing from brake housing
