Is It Bad to Crack Your Knuckles? Doctors Weigh In

Many of us have heard that cracking your knuckles is bad for you, and can even increase your chances of developing arthritis down the line. As a kid, this alleged factoid quickly scared me out of what I thought to be a harmful habit. But looking back, I wonder if there was ever any truth behind my fear.

Now I wonder: Is it actually bad to crack your knuckles? And what happens if you do crack your knuckles too much? To get to the bottom of this medical mystery, we spoke to doctors about the science of knuckle cracking and its potential consequences — plus a few common misconceptions. Ahead, doctors explain if cracking your joints is bad for you, and whether or not it’s harmful to pop your knuckles every now and then.

Experts Featured in This Article:

James Chen, MD, is a board-certified orthopedic surgeon at DISC Sports and Spine Center.

Jason Liebowitz, MD, is a board-certified rheumatologist and assistant professor of medicine at Columbia University Irving Medical Center.

Why Do Knuckles Crack?

The knuckles are a part of the metacarpophalangeal joints located in your hand. “All joints consist of a capsule filled with synovial fluid that provides lubrication for the surface where two bones meet,” says James Chen, MD, a board-certified orthopedic surgeon at DISC Sports and Spine Center. The sound produced by cracking your knuckles is not caused by the bones clashing together — which you may have also been told as a kid — but rather by the popping of nitrogen bubbles in the synovial fluid found within the joints, says Jason Liebowitz, MD, a board-certified rheumatologist and assistant professor of medicine at Columbia University Irving Medical Center.

All joints can “crack,” but the knuckles and other joints in your fingers are most prone to cracking given their size and the large amount of motion they endure, says Dr. Chen. “Essentially, the motion and flexibility in the fingers allows for more pressure changes and fluid dynamics, ultimately leading to the cracking.” Physically pressing on the joints can cause changes in pressure as well, triggering a popping or cracking sound.

Is It Bad to Crack Your Knuckles?

Nope. It’s not inherently bad to crack your knuckles. “In general, cracking your knuckles should not be harmful or lead to significant damage,” says Dr. Chen — as long as it’s done in moderation. With that in mind, “if [cracking your knuckles] develops into a compulsive habit, this could lead to irritation, and it would be recommended to cut back.”

There’s also no medical evidence that cracking your knuckles will lead to arthritis , Dr. Liebowitz says. Osteoarthritis is the most common form of arthritis, but it typically occurs when the cartilage and other tissues in a joint break down or change structure. It is not caused by cracking your knuckles, he says. Other forms of inflammatory arthritis are triggered by autoimmune diseases, infections, and medications, Dr. Liebowitz says — again, not by cracking your knuckles.

Is It Bad to Crack Your Fingers Every Day?

In general, it’s not bad to crack your fingers every day, says Dr. Chen. However, if it hurts to crack your knuckles, then cracking your knuckles every day could make this pain worse.

How often you crack your knuckles also matters. A crack here or there is no problem. But if you’re cracking them excessively and it becomes a habit, you may aggravate the joint, which could cause discomfort, Dr. Chen says. He defines “excessive” knuckle cracking as anything that causes you pain — although the exact number of cracks it would take to reach that point is likely different for everyone. “If there is persistent pain when cracking your knuckles, I would encourage a medical evaluation, as unrelated conditions may also be present, such as arthritis or other injuries,” Dr. Chen says.

Is It Ever Good to Crack Your Knuckles?

While cracking your knuckles likely won’t provide any structural benefits, there may be some good that comes from the occasional crack, Dr. Chen says. “Cracking joints can provide a sense of relief from the release of tension in the joint, particularly when stretching,” he says. This could potentially improve your mobility later in life.

What Happens When You Crack Your Knuckles Too Much?

Cracking your knuckles may not be as bad as we were told, and there isn’t any evidence to suggest that it causes significant structural damage to your joints or bones. But cracking your knuckles in excess can still irritate your joints, potentially causing discomfort and/or pain, Dr. Chen says. If that’s the case, it would be wise to scale back and leave your knuckles be.

Additionally, if cracking your knuckles leads to persistent or severe joint pain, swelling, or stiffness, Dr. Liebowitz says it’s worth checking in with a doctor to evaluate the root cause. They can then guide you through the best treatment options based on your personal circumstances.

Andi Breitowich is a Chicago-based freelance writer and graduate from Emory University and Northwestern University’s Medill School of Journalism. Her work has appeared in PS, Women’s Health, Cosmopolitan, and elsewhere.