Grinding brakes almost always mean the pads have worn down to their metal backing plates, which are now cutting into the rotors. It is the most urgent brake sound: every mile adds rotor damage and stopping distance grows. Budget for pads and rotors, and get the car in within days, not weeks.
Likely causes
Pads worn to metal — The friction material is gone; metal-on-metal contact grinds and scores the rotor.
Debris caught in the caliper — A small stone can screech or grind temporarily — if it stops within a day, that was likely it.
Rusted rotors after sitting — Surface rust grinds off in the first few stops after a car sits; persistent grinding is not rust.
What you can check yourself
Stop driving on them if you can — rotor damage gets more expensive by the mile.
Check pad thickness visually through the wheel if possible.
Do not just replace pads: scored rotors will eat new pads quickly.
Typical cost
Typical repair: pads + rotors $400–$700 per axle in Nashville, TN; if calipers were damaged by heat, add $150–$350 per caliper.
When to call a pro
Immediately. Grinding is the one brake symptom that should not wait for a convenient day.
Data by Servik — verified local pros from official license records and public sources. Cost figures are typical ranges, not quotes; a pro's written estimate is the real number.