Archive · 10 Aug 2026

Does Knuckle Cracking Damage Joints? Doctors and Research Say No

Does Knuckle Cracking Damage Joints? Doctors and Research Say No

Have you ever heard a loud pop when someone cracks their knuckles?

Some people love that sound, while other people worry that it is hurting their hands.

The pop does not mean your bones are breaking or rubbing together.

Inside your finger joints there is a slippery liquid called synovial fluid.

When you stretch your finger, the space inside the joint grows and the pressure drops, which makes a tiny gas bubble form in the liquid.

That bubble, called joint cavitation, is what makes the popping sound.

Doctors and researchers have studied people who crack their knuckles for many years and have not found proof that the habit causes arthritis, a disease that makes joints painful and stiff.

Two studies, one from 1975 and another with 215 people, found no extra risk.

Cracking too hard can hurt you, so gentle cracking is best.

If a joint pops and also hurts, swells, or feels weak, you should see a doctor.

Sources