Crepitus is a term used to describe a grating sound or sensation produced by friction between bone and cartilage or the fractured parts of a bone. It can be heard in joint pathologies and can be caused by various factors such as inflammation of the fluid-filled sheath that surrounds a tendon, osteoarthritis, or rheumatoid arthritis when the cartilage around joints erodes and the surfaces in the joint grind against one another. Crepitus can also be produced when gas is introduced into an area where it is normally not present, such as in soft tissues. The sound associated with crepitus may be muffled or loud enough for other people to hear. It can be a normal part of movement and is often harmless, but if it is regular and accompanied by pain, swelling, or other concerning symptoms, it may be an indication of arthritis or another medical condition. Applying ice to the area and taking non-steroidal anti-inflammatory drugs, such as aspirin and ibuprofen, will usually be enough to alleviate pain and inflammation caused by crepitus. If crepitus is painful, you should consult a doctor.