A couple of years ago, I had a neck thing going on, where every time I turned my head to the left I heard a funky grinding sound. My neck was a little stiff, but not enough to explain the noise it was making. I began to worry that the noises coming from my neck was a sign that something was really wrong.
It turns out that I had something called crepitus, which is a big word to describe any kind of noise coming from a joint. The sounds can be creaky, grinding, crackling, grating and even popping. Joint noise can be so soft that only you hear it or loud enough to startle a roomful of people.
Crepitus can be caused by a number of structural issues. One of the most common causes of joint noise is air bubbles popping inside the joint. What happens is that gas builds up in the synovial fluid that cushions your joints, and the gas forms bubbles. When a joint is popped or stretched, 
you can hear the release of these bubbles as a popping sound. An example of this kind of crepitus is when someone cracks their knuckles. It sounds horrible and painful, but it typically doesn’t cause pain or long-term damage. Interestingly, if you’re a knuckle cracker, you’ll have to wait until the gas bubbles reform before you can crack them again.
Another frequent cause for joint noise is when the bones within the joint grind against each other. This can happen from injuries and trauma to the joint, but it’s far more common in people with osteoarthritis, especially of the knee. Your joints contain a kind of connective tissue, called cartilage, which acts as a shock absorber and protects the ends of your bones from rubbing together within the joint. Osteoarthritis is a condition in which wear and tear from overuse and aging causes the cartilage to erode and the joint to become inflamed. When your joint’s cartilage has worn away, it’s not uncommon to hear a grinding or grating noise as the bones rub against each other.
You may also hear crepitus when a ligament or tendon snaps over a bony structure within the joint. This often happens because the ligaments or tendons become inflamed, swell and don’t move as smoothly as they should. Because this kind of joint noise is often associated with inflammation, ligament or tendon crepitus can be painful.
Another structure within your joints that can be the source of noise is the bursa. Your bursae (plural) are pockets of thick fluid that surround your joints to protect them from injury. Trauma or infection can cause inflamed bursae to rub together within the joint, which you may be able to hear as a grinding, snapping or popping sound.
Crepitus can occur in any joint. Your knees are often some of the noisiest joints. They’re a common site of osteoarthritis, but they’re also notorious
for making a loud crack when an air bubble pops within the knee. The temporomandibular joint (TMJ) that connects your lower jaw to your skull can also be the source of a lot of noise. People with TMJ problems may experience clicking and popping sounds every time they open their mouth. That said, shoulders, wrists, ankles, elbows, fingers, toes and even your spine can cause crepitus given the right conditions.
Is Crepitus a Bad Thing?
If you’re hearing noise coming from a joint, you may be wondering if it’s a problem. And the answer is that it depends. Cracking your knuckles or a loud knee pop without pain is just the release of gas within the synovial fluid in your joints. However, joint noise that’s becoming more frequent or accompanied by pain, inflammation, swelling or loss of function is often a problem. The noise may be a sign of joint damage, osteoarthritis, tendonitis or even a chronic disease. In addition, crepitus accompanied by joint pain or pain that originates in the joint but travels down your leg or arm may also be a sign of nerve compression from narrowing joint spaces. So the short answer is that if you’re experiencing joint noise plus any symptoms, a good plan is to get it checked out.
In the end, the crepitus in my neck stuck with me for several weeks. I did some stretching to loosen up my neck and shoulders, quit carrying a shoulder bag, and the noise went away. Now when I stretch my neck, I hear the faint sounds of my muscles loosening up, but no grinding sounds or pain, so I’m good to go!
