Ask The Doctors: January 2019
Q: Why do my joints make noise -clicking and popping?
A: Bones and joints can make grinding, creaking, clicking, popping and other noises, which can occur at any age but become more common as we get older. The medical term is crepitus, and there can be several causes. If you're just hearing noise without pain, swelling or other symptoms, don't be alarmed. If you have other symptoms, you should get it checked out.
The underlying issue with noisy joints may relate to tendons (which connect muscle to bone), ligaments (which connect bones to other bones), or cartilage (the smooth covering over the ends of bones in joints). The knee generally is the noisiest joint, but other joints can also develop sounds, including the hip, shoulder, neck and spine.
Here are some possible reasons for the noise:
- A tendon or ligament may snap over a bony bump.
- A ligament can tighten with movement.
- Air bubbles inside the joint can pop.
- Muscle tightness in the neck can cause it to grind with movement.
Cartilage can wear away, causing rough areas. This is osteoarthritis and it can result in the bones no longer gliding smoothly against each other. As a result, the joint can make a grinding or crunching sound.
Osteoarthritis does not always cause pain and stiffness. However, if your non painful knees become noisy, don't be surprised if you eventually have some symptoms. A study published in Arthritis Care & Research (January 2018) found that more than 75 percent of people who developed knee osteoarthritis reported grating, cracking or popping sounds in or around their knee joint in the year before developing symptoms.
Q: I understand that high levels of uric acid lead to gout. What causes uric acid to be too high?
A: There's a common belief that gout is caused by overindulging in foods high in purines, such as red meat, seafood and alcohol. This is because purines break down to uric acid, which is the substance that at high levels in the body can lead to gout. But it's not that simple. In fact, a recent study, published in the journal BMJ (October 2018), found that genetics was far more likely to be responsible for variations in uric acid levels than food. High-purine foods raise uric acid levels only a very small amount.
Uric acid is a substance that naturally occurs in the body as a byproduct of old cells dying off. For most people, the body can properly balance production of uric acid and elimination of it, which is done through the gastrointestinal tract and kidneys. Most uric acid is expelled in urine. However, if the kidneys don't get rid of enough uric acid, it can build up in the bloodstream. People can inherit genes that make their kidneys more or less efficient at eliminating uric acid.
Some, but not all, people with high uric acid levels develop gout. Gout occurs when excess uric acid leaves the bloodstream and settles in other parts of the body, particularly joints. The uric acid may form needle-shaped crystals. These periodically trigger a gout attack, which is marked by swelling, redness and pain in the joint.
The exact cause of gout is still not entirely understood, especially because not everyone with high uric acid levels develops it. Even though the food you eat probably doesn't cause gout, it's still a good idea to eat a healthy diet, which may help cut down on gout attacks.