Most people at some point have heard cracking or grinding noises in their neck upon movement. These sounds, also called crepitus, are usually painless and typically do not represent anything serious.

However, if the neck cracking noise is accompanied by pain, swelling, or some other concerning symptoms, then it may represent a problem that should be checked by a qualified health professional.

Possible Causes of Neck Cracking

Crepitus, sometimes called crepitation or cavitation, refers to any type of noise or sensation such as a cracking, popping, snapping, or grinding sound that is heard during neck movement. For example, feeling a cracking sensation in the neck when turning the head to back up the car.

Crepitus can occur in any moveable joint in the body, and there are many moveable joints in the neck. The neck joints are bathed in an oily-like substance call synovial fluid, which allows motion to freely occur in between the bones.

The underlying cause of crepitus in the neck is still not yet fully understood.

Some likely causes of the neck cracking sound include:

Synovial joint fluid pressure changes
Various studies have been performed purposely cracking the synovial joints of the fingers, but the conclusions in medical literature as to what is actually making the noise have been mixed. In particular, a study published in 1971 indicated that the cracking sound of a joint was caused by the bursting of a gaseous bubble in the joint’s synovial fluid.¹ However, a study published in 2015 reported that the cracking sound was actually from the bubble being created.²

Ligament or tendon moving around bone
Another possible factor in neck cracking could be the snapping sound of ligaments and/or tendons as they move over bones or other muscles or tendons located in the neck region.

Bone on bone grinding
While an uncommon cause of neck cracking, it’s possible for bone to grind against bone if the cartilage has worn down. This condition is called osteoarthritis. It occurs gradually with the normal aging process, or it can be accelerated if there has been a traumatic injury such as whiplash or a sports-related injury

This type of crepitation is typically accompanied by pain, limited neck motion, and the cracking sound is usually repeated over and over with each movement. This experience is in contrast to the typical gas bubble formation crack, where it typically takes about 20 minutes before cavitation, or the cracking, can again occur.