What Happens When You Crack Your Knuckles?

There are many beliefs about cracking knuckles and how they affect your body. This article will debunk the myths and help you understand the science behind knuckle cracking.

Why Do You Crack Your Knuckles?

Dr. Robert Shmerling, a rheumatologist and senior faculty editor at Harvard Health, said knuckle cracking is a common behavior many enjoy. He also said it can develop into a habit or a way of dealing with nervous energy. Shmerling said other people had described it as an annoying thing that other people do.

In some cases, people crack their knuckles due to habit. Like constantly smoking cigarettes, excessive knuckle cracking can grow into a habit that is hard to break. Stress relief is another reason why people crack their knuckles.

What Causes the Popping Sound When You Crack Your Knuckles?

Dr. Thanda Aung, an assistant clinical professor in UCLA’s Division of Rheumatology, said there are insufficient studies to explain the mechanism responsible for the cracking noise. However, she said there are two hypotheses.

Aung said the first claims the popping noise could be from the movement of the structures in your fingers. This includes tendons, bones, and ligaments. The second hypothesis concerns the synovial fluid and the gas created from it. Aung said the cracking sound might result from the movement of this gas in and out of the tight space in the finger joints.

Does Cracking Your Knuckles Cause Arthritis?

Regarding this belief, Dr. Aung references a study on habitual knuckle cracking and hand function. The study concluded that habitual knuckle crackers were likelier to have lower grip strength and hand swelling. However, Aung said the study also concluded there is no clear evidence linking knuckle cracking to osteoarthritis.

How Can You Stop Cracking Your Knuckles?

Aung said most of her patients say they crack their knuckles in response to anxiety and stress. She also said she tells them to practice meditation and breathing exercises as an alternative.

It has also been understood that knuckle cracking is done subconsciously. As a result, Aung suggests you should always keep your hands busy doing something else. This could be drawing, doodling, or playing with stress balls.

Finally, Aung said you should try common stress and anxiety relievers. These include exercise, healthy eating, journaling, and connecting with others.


Currently, no evidence supports the claim that knuckle cracking causes arthritis. However, finding healthier ways to deal with your stress and anxiety may be worthwhile. This will finally help you break this habit.