The short answer from an orthopaedic surgeon
Q: My joints make clicking and popping sounds. Why is that?
A: Bones and joints can make grinding, creaking, clicking, popping and other noises, which can occur at any age but become more common as we get older. The medical term is crepitus, and there can be several causes.
If you’re just hearing some noise and there’s no pain, swelling or other symptoms, don’t be alarmed. If you are having other symptoms, you should get it checked out.
The underlying issue with noisy joints may relate to tendons (which connect muscle to bone), ligaments (which connect bones to other bones), or cartilage (the smooth covering over the ends of bones in joints). The knee generally is the noisiest joint, but other joints can also develop sounds, including the hip, shoulder, neck and spine.
Here are some possible reasons for the noise: