In order to answer this question, we first need to talk about arthritis [1]. It's the name for a group of conditions where there is damage caused to the joints. Here are some examples:
- Rheumatoid arthritis and psoriatic arthritis are autoimmune diseases in which the body is attacking itself.
- Septic arthritis is caused by joint infection.
- Gouty arthritis is caused when uric acid crystals get deposited in the joints, which causes inflammation.
- The most common form of arthritis, osteoarthritis (also known as degenerative joint disease), occurs after an injury or infection in the joint, or simply as a result of aging.
Hmm, I see that of these 4 examples, none of them are caused by popping your joints.
Now let's talk about knuckle cracking. A joint is an area where 2 or more bones meet. This area is surrounded by joint fluid that protects the bones from rubbing against each other. When you "crack" or "pop" your knuckles or other joints, you are NOT grinding your bones together. Carbon dioxide is dissolved in that joint fluid. The sound you hear is a result of the high pressure being released, when the gas comes out and forms a bubble. That release of pressure allows a temporary increase in the joint's range of motion, which is why it feels so good. The reason you can't re-crack your knuckles immediately after is because it takes a little time for the gas to get re-dissolved back into the joint fluid.
There is no evidence [2] that cracking your joints causes arthritis, or any other permanent damage - it just offers relief.
So the next time you crack your knuckles and someone says "Stop! You're going to get arthritis!," just smile and politely explain that you're just releasing the pressure of your joint fluid.
Source [2]