HealthONE - November 15, 2017

Popping joints may not be a complicated medical condition, but why they pop isn’t so simple.

“Your joints pop for a few different reasons,” said Dr. Ian D. Dickey, orthopedic surgeon at Presbyterian/St. Luke’s Medical Center. “When you bend and stretch, the fluid and mechanics of your joints move, too.”

If a tendon moves across a joint, it can create a popping noise called crepitus. Likewise, you have a lubricant between your bones called synovial fluid. If you momentarily break the seal of synovial fluid that fills the joint capsule, you may also hear harmless popping noises. Additionally, rough joint surfaces caused by arthritis can cause audible friction when your body moves.

What about knuckle cracking?

Your tendency to crack knuckles may be a bad habit, but it won’t do any long-term damage to your joints. The popping sound you hear is caused by the formation of gas bubbles. When a knuckle cracks, the space in the joint expands and gas that has dissolved into the synovial fluid fills the space and makes a popping sound.

“While cracking your knuckles may not cause arthritis, it can cause chubby fingers,” said Dr. Dickey.  “Constant knuckle cracking can lead to inflammation that can make your fingers appear larger.”

Should I be worried?

According to Dr. Dickey, the sound you hear when a joint cracks is usually nothing to worry about, but cracking noises accompanied by pain and swelling could be a sign of a more serious injury that can impact your bone and joint health.

“If your primary care doctor doesn’t feel comfortable treating your injury, he or she may send you to a bone specialist like an orthopedist or physical therapist,” said Dr. Dickey.