

Our bodies' snaps, crackles, and pops

Featuring content from MediResource Inc.

The human body seems to become noisier as it ages. Surprising creaks and snaps seem to emanate from our bones as we get up from bed in the morning. Or when we stand up or stretch a bit farther – or in a different direction – than we usually do. Other sounds crackle from inside our ears, and when we intentionally crack the joints in our knuckles or toes, we hear that familiar and relieving pop. Most of the noise is harmless or humorous, but what is the purpose of our body's snap-crackle-pop chorus?

The sound of creaking bones may call to mind spooky stories of wandering, clattering skeletons. But it's not really your bones making all that noise. The symphony of creaking, crackling, and snapping comes courtesy of your tendons, ligaments, and joints.

Tendons attach muscles to your bones, and ligaments tether one bone to the next and surround and strengthen joints. As you move and bend, these connective tissues stretch and spread across the surface of the joints. So, as you climb the stairs or stand up from the ground, you may hear a tendon or ligament snapping into place around the moving joints.

Your joints are encased in a protective synovial fluid containing nutrients and gases including oxygen, nitrogen, and carbon dioxide. It's like a safety shell around your joints. If you "pop" a joint, the pressure from moving or stretching the joint causes the gas bubbles to burst from within the synovial fluid. You basically squeeze a bit of room into your joints. After about 20 minutes, the gases within the shell return to the synovial fluid, and that's why you can't pop the same joint again right away. In the short term, this feels good and is harmless. But over a lifetime of intentionally cracking and popping your joints, you may damage your joints.

Finger and toe joints pop often, but the sound of a clicking jaw may surprise you now and then, too. The upper and lower jaw joints have a cushion-like disk between them that occasionally slips out of place. As it slides back into place, it makes a clicking sound. For people with temporomandibular joint dysfunction (TMJD) this popping may accompany headaches, neck aches, joint tenderness, difficulty opening the mouth wide, and ear pain.

Noises may crackle and pop from inside of your ears, too. You can hear it when you swallow, as air passes into your middle ear from the back of your nose through your Eustachian tube. But when you're on a plane taking off or landing, it may sound much louder. That's because a quick change in altitude or pressure causes your Eustachian tube to work overtime, opening and closing over and over to equalize the pressure on both sides of your eardrums. You may also hear babies on board crying more because they don't know how to unblock their ears. Give baby a bottle or pacifier to suck, an action that opens their Eustachian tube. You can simply swallow, chew gum, or yawn to make yours open up again.
