Are you a knuckle cracker? You might crack your knuckles when you’re bored. You might feel a sense of relief with that pop. You might just like the feeling of it.
But is it bad for your joints or your long-term health? Here’s what happens when you hear that cracking sound, whether it’s harmful and when it might be a sign to stop.
Why do people crack their knuckles?
"I think it's mostly just to get rid of stress," said Ryan Richards, MD, a hand surgeon with Banner Health. "And it's kind of a habit that some people find to be a stress relief or a distraction."
Habitual knuckle cracking often starts in childhood and it can become something you don’t even realize you’re doing.
What causes the cracking or popping noise?
The cracking sound doesn’t mean anything is breaking. Your knuckles are joints, and like other joints in your body, they contain synovial fluid. This fluid helps lubricate your joints so they can move smoothly.
"The joint naturally has a negative pressure, which holds the two bones together kind of like a suction cup," Dr. Richards said. "As you pop your knuckles, you increase the negative pressure even more."
When the negative pressure increases, nitrogen bubbles come out of the synovial fluid really quickly and burst. This is probably what causes the popping noise.
"You know when you pull on a suction cup and it makes a popping sound? There’s some of that going on, too," Dr. Richards said. "You’re separating two things that are already under negative pressure and when they finally separate, you get this noise that’s caused by the release of suction."
After you crack a knuckle, it may take about 20 minutes before you can pop the same joint again. That’s because it takes time for the gas bubbles to return.
Is cracking your knuckles bad for you?
You may have heard that cracking your knuckles can lead to arthritis. But research hasn’t proven this.
"For most people, it's totally safe. It doesn't cause arthritis," Dr. Richards said. "You’d have to be super aggressive and do something really out of the ordinary to cause damage."
There are other noises your joints might make besides the standard “pop.” As you get older, your joints may creak more as cartilage naturally wears down. Tendons can also flick over bones, creating other sounds.
Can cracking your knuckles dislocate your fingers or cause damage?
Cracking your knuckles doesn’t put enough force on the joint to dislocate your joint or damage your fingers. However, if you push too hard or already have joint issues, it’s possible to cause pain or strain.
Pain, swelling or reduced movement after cracking may be signs of another issue, not the knuckle-cracking habit itself. If cracking ever leads to pain, stiffness or swelling, you should contact a health care provider.
How can you stop cracking your knuckles?
Cracking your knuckles is usually harmless but you might want to stop if it’s a nervous habit that bothers you or other people or if you have other joint problems and cracking your knuckles is causing pain, stiffness, soreness or swelling.
If you want to break the habit, try these tips:
- Take notice of when and why you crack — being aware can help you change the behavior. “Find whatever it is that triggers the need to crack your knuckles. What is it that makes you want to do this? That’s the first step," Dr. Richards said.
- Use a stress ball or small fidget tool to keep your hands busy.
- Stretch your fingers or wrists instead of cracking your knuckles.
- Instead of quitting all at once, Dr. Richards suggests cutting back a little bit at a time. Set goals or limits, like no cracking during work meetings.
When should you talk to a doctor?
Popping sounds without pain are usually not a problem. But if you notice any of these symptoms, see a health care provider:
- Pain when cracking or moving your fingers
- Swelling or redness in your hands
- Trouble holding things or a weak grip
- Joint stiffness or locking
These could be signs of arthritis, injury or another joint issue.
"There are other things that could cause your knuckles to pop," Dr. Richards said. "If your knuckles are snapping and catching, it could be a trigger finger, which is when a finger gets stuck and won’t open. You might make a fist and one of your fingers either opens suddenly after the rest of your fingers, or you might have to pull it open," Dr. Richards said.
A health care provider can perform a physical exam and order imaging tests to help figure out what’s causing your symptoms.
The bottom line
Cracking your knuckles might sound strange but for most people, it’s not dangerous. It doesn’t cause arthritis and there’s no strong evidence that it harms your joints. As long as you don’t have pain or stiffness, it’s usually fine to keep doing it. But if you’re concerned, you can take steps to slowly break the habit.
If you have pain, swelling, weakness or other concerns about your knuckles or hands, check in with your health care provider or an expert at Banner Health.
