Crepitus, sometimes called crepitation (krep-i-tay-shen), describes any grinding, creaking, cracking, grating, crunching, or popping that occurs when moving a joint. People can experience crepitation at any age, but it becomes more common as people get older.

One common cause of crepitus is arthritis, such as osteoarthritis of the knee or hip.

The sound associated with crepitus may be muffled or it may be loud enough for other people to hear.

What Causes Joint Crepitus?

Common causes include:

• Air bubbles popping inside the joint. This popping does not cause pain.
• Tendons or ligaments snapping over the joint’s bony structures. This snapping sometimes causes pain.
• Arthritis—typically either osteoarthritis or rheumatoid arthritis—that causes a joint’s articular cartilage to degenerate. While arthritis often leads to pain, not everyone with joint degeneration will experience it.When a joint’s cartilage degenerates, the joint is no longer adequately protected against friction and impacts. In addition, the loss of cartilage can alter the joint’s biomechanics and cause bones to grind against one another. These changes can result in crepitus.

Many people experience crepitus in their knees. People can also get crepitus in other joints, such as the hip, shoulder, neck and spine, which are frequently affected by arthritis.

Does Crepitus Need to Be Treated?

Crepitus usually is not a cause for concern. In fact, most people’s joints crack or pop occasionally, and that is considered normal. But if crepitus is regular and is accompanied by pain, swelling, or other concerning symptoms, it may be an indication of arthritis or another medical condition.