“Don’t crack your knuckles or you will get arthritis” my parents always told me. Well good news, knuckle cracking (or popping other joints) doesn’t cause arthritis.
The popping or cracking sound that a knuckle makes is the result of gasses built up in the knuckles being released. By itself, the release of these gasses is harmless.
However, if you crack your knuckles when you are experiencing anxious thoughts or emotions, you may develop the tendency to use too much pressure on your fingers.