Your body has millions of parts working together every second of every day. In this series, Dr. Jen Caudle, a board-certified family medicine physician and an associate professor at Rowan University School of Osteopathic Medicine, explains how the body works — and all of its quirks.
If you’ve ever popped or cracked your joints — by accident or on purpose — you’re not alone. There’s even a medical name for that crackling, clicking or popping sound your bones make: crepitus.
Popping joints can happen involuntarily, and you can experience it in your knees, neck, fingers, wrist or ankles. Or you might have a habit of cracking your joints, such as your knuckles, yourself. If you do, you probably know that you can’t pop all your joints, and once you’ve cracked a joint, you might not be able to crack it again for about 20 minutes.
But why do your joints make a sound when you pop them? And is it a harmful habit? Here’s what the experts say.
Why do people pop their joints?
Dr. Jen Caudle tells Yahoo Life that our joints may make a popping sound when we pull them apart or bend them in specific ways.
Popping, snapping or cracking joints is very common and can be painful or painless, Dr. Charles Lawrie, an orthopedic surgeon at Baptist Health Orthopedic Care, tells Yahoo Life. “For some people, this experience occurs as they move throughout their day,” he says. “For others, they may be able to intentionally cause the sound to occur, such as cracking one’s knuckles.”
Often, popping joints is a repetitive habit, like nail biting, Dr. Andrea Halim, an orthopedic surgeon at Yale New Haven Hospital, tells Yahoo Life. It may also be a nervous habit or something people do while they’re thinking through a problem.
Research suggests that people who crack their knuckles might do it to release tension in the joints or “free” the joints.
What makes the popping sound when you pop your joints?
No one knows precisely why our joints make a popping sound in the first place, but researchers have found several potential reasons for it. The most common explanation for the popping sound is what experts call “cavitation,” according to Lawrie.
Most of the joints in our bodies are enclosed in capsules. Lawrie explains that these capsules act like water balloons holding in the joint fluid that helps nourish and lubricate the joint. “Cavitation occurs when there’s an external force on the joint fluid, causing small bubbles to form within the fluid and pop,” he says. The popping or cracking sound you hear is apparently the sound of the bubbles popping.
Caudle agrees, adding that pressure from when our joints are stretched and pulled causes the bubbles in the joint fluid to pop. “Many of us have our methods to get that sweet gratification of popping, cracking and snapping,” she says. “Sometimes we don't even need a method; it just happens.”
The joints may also make sounds because of damage to or irregularity in the joint surface or internal structure of the joint, says Lawrie. People with arthritis usually experience this type of popping joints, he adds. In addition, people with joint dislocation may also hear a snap or pop when a healthcare professional returns the joint to its normal location.
“Outside of the joint, ligaments or tendons may snap over bone parts or joints quickly, resulting in a snapping sensation,” Lawrie says.
Although you might find the sound unpleasant, Caudle says you can't necessarily stop your joints from popping from time to time.
Is the habit harmful?
You may have heard that cracking your knuckles is bad for you and can even cause arthritis, notes Caudle. “But studies have shown that may not be the case,” she says, especially if you pop them yourself and feel no pain when they pop.
Halim agrees: “There is no evidence suggesting that knuckle popping or cracking your joints leads to arthritis.”
However, Lawrie says that “depending on the cause, popping or cracking your joints may or may not be harmful.” He advises avoiding intentionally popping your joints, as it may lead to further joint damage if there’s an underlying condition.
When should you see a doctor?
In some cases, popping joints may be a symptom of a joint problem. For instance, a person with osteoarthritis may hear their kneecap make a crunchy, crackling or pop-like sound due to cartilage wearing down.
Lawrie recommends seeing an orthopedic doctor if you have joint noises that come with pain or if it feels like your joint is dislocating when the noise happens.
This video was produced by Olivia Schneider.
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