Crepitus, sometimes called crepitation (krep-i-tay-shen), describes any grinding, creaking, cracking, grating, crunching, or popping that occurs when moving a joint. People can experience crepitus at any age, but it becomes more common as people get older.
The sound associated with crepitus may be muffled or it may be loud enough for other people to hear.
The term crepitus is sometimes also used to describe other conditions, such as lungs crackling from respiratory illnesses and bones grating after fractures.