What makes joints snap, crackle, and pop? Ankles, knees, shoulders, elbows, you name it, I've probably got it. It wasn't bad in my twenties, but in my early thirties I've seen a definite increase. Should I be concerned? Is there any therapy that would help?

— Dave Perkins, Amherst, Massachusetts

There are a few things that could cause you to sound like a bowl of just-doused Rice Krispies. A pressurized capsule, appropriately called the joint capsule, surrounds all of our joints. This internal pressure makes for some great audio when it changes to adjust to an expanding or contracting joint space, such as when you crack your knuckles. This form of joint acoustics may actually be addictive: it's been hypothesized that the pressure change releases nitrogen into nearby spaces causing a small, but noticeable endorphin release. But alas, as with so many of life's simple pleasures, those in the know say better to limit your joint popping, it's most likely not all that good for you-- the "getting it to pop" stress in the joint may lead to long-term degeneration.

Audible joints can also be attributed to structural changes. Tendons and ligaments that surround or lie within a joint usually function with little interference as you move. But as time marches on, joints' surfaces and alignments can change, sometimes causing your tendons or ligaments to get hung up on a bony prominence for a moment, only to be quickly released with an accompanying snap, crackle or pop. Then there's crepitus, whish is noise or vibration within a joint as it articulates, caused primarily by two irregular surfaces being rubbed together. Most joint surfaces are topped with a layer of cartilage, a fabulously slippery material that allows bones to glide past each other. This precious cartilage can break down with age, slowly disappearing until you've got bone on bone, which makes for a noisy partnership.

These changes aren't life threatening but can mean future joint problems. The best remedies: Adequate strength training and stretching two or three times per week, especially of your major muscle groups. Make sure you have proper alignment while you are doing your sports activities, especially those with high impact, such as running. You can make sure your alignment is on track by going to a sports doc for a gait analysis. Another option is to supplement your diet with chondrotin sulfate and glucosamine sulfate (available at health food stores), which aid joint lubrication and help you sneak up on people.