Snapping and popping of joints are common. The sound you hear is caused by air bubbles in the liquid that surrounds and lubricates your joints. When not accompanied by pain, noisy joints are harmless. Many people also notice that as they become older, their joints seem to make more noise. This is because some of your cartilage wears away as part of the natural aging process making the surfaces of your joints a little rougher, causing them to rub against each other. Consult a doctor if the noise is accompanied by pain and swelling.