As we age, the body’s spongy cushions (intervertebral disks in the case of the spine and cartilage in the case of the joints) tend to dry out from wear and tear. Sometimes they disappear altogether, resulting in loss of height and disturbing sounds caused by bone grating on bone, especially with neck and knee movements.
Those creaking and cracking sounds by themselves require no medical attention. It is only when they are accompanied by pain or limitation of motion that over-the-counter anti-inflammatory pain medication such as ibuprofen (Advil and generic) or naproxen (Aleve and generic), physical therapy, or, in severe cases, joint replacement may be warranted.
But not all joint noises are the result of aging. Many people of all ages can crack or pop finger joints. The explanation frequently offered? That the noises are due to the escape of gases that are dissolved in joint fluid.
Contrary to popular thought, knuckle crackers are no more prone to osteoarthritis than others. But some studies show that repetitive knuckle cracking can weaken handgrip.
Source: Consumer Reports on Health April 2015