There’s nothing like a good snap, crackle, and pop first thing in the morning. (No, we’re not talking about those cute little elves with the cereal.) We’re talking about the glorious feeling of cracking your back—well, for some people at least.

It sounds like a painful pastime, but cracking your back can feel really good, whether it’s the first thing you do when hopping out of bed or you use it as a stress reliever after a long day at your desk. You’ve probably been doing it for years, but have you ever stopped to think, “What happens when you crack your back?”

The good news is it’s pretty clear you’re not actually hurting your spine, even if it may sound like it. “Cracking your back is very common,” Ferhan Asghar, M.D., assistant professor of orthopedic surgery at UC Health, tells SELF. What’s oddly not so clear (there’s still quite a bit of scientific debate on this topic) is what actually produces that cracking noise and feeling of sweet, sweet relief. But before we get into all the theories about cracking your back, let’s go through a quick anatomy lesson.

First, what does the spinal cord do?

In order to understand what happens when you crack your back, it’s important to know a bit about how your back is put together. The star of the show is your spine, which is located down the center of your back. You can think of it as “the scaffolding for the entire body,” according to Cedars-Sinai Spine Center. Your spine protects your spinal cord, a bundle of nerves that transmit messages between your brain and pretty much every part of your body. With the help of vertebrae, or interlocking bones, it also supports about half the weight in your body. The average person is born with 33 vertebrae, but most adults only have 24 since some of the lower ones fuse together over time.

Your vertebrae are divided into sections: your cervical spine (hi, neck bones), your thoracic spine (the upper part of your back), your lumbar spine (lower back), your sacrum (this joins with your pelvis), and your coccyx (a funny way to say tailbone). Your vertebrae connect with each other at the back via flexible joints, and rubbery cushions known as discs are in between each one to provide some cushioning. Finally, your vertebrae connect with muscles, ligaments, and tendons throughout your back to help you do everything from explosive burpees during your HIIT workout to leaning over to give your cat a goodnight nuzzle.

What happens when you crack your back?

“There are a number of theories on why this happens, but nobody really knows,” Neel Anand, M.D., professor of orthopedic surgery and director of spine trauma at Cedars-Sinai Spine Center in Los Angeles, tells SELF. If that’s not the answer you were hoping for, fear not, there are some pretty interesting theories about back cracking.

The most widely accepted one involves pockets of gas that like to hang out in your joints. We’re not talking about the same kind of gas that escapes from your body after eating a particularly bean-heavy chili (though, that can be similarly satisfying to cracking your back). This gas comes from a lubricant inside your joints known as synovial fluid—which contains oxygen, nitrogen, and carbon dioxide—that helps give nutrients to the cartilage in your joints to help them glide smoothly. When you apply force to your joints, those gases are rapidly released, according to the Library of Congress.

The thinking is that as these gases shift during an extreme stretch, they emit a cracking noise as they dissipate, Dr. Anand says. The existence of this gas isn’t up for debate—it actually shows up on X-rays and MRIs before surrounding tissues quickly reabsorb it after you crack your back, Lisa A. DeStefano, D.O., chairwoman of the Department of Osteopathic Manipulative Medicine at Michigan State University, tells SELF. However, whether that “pop” sound is caused by the gas bubbles themselves or something else is hotly debated. Researchers who published a 2015 study in PLOS One argue it’s the latter. That’s because when they examined MRIs of knuckles cracking, they discovered the sound actually happens when a gas-filled cavity forms as the joints stretch, not when the gas bubbles themselves collapse.

There are also some less widely believed theories that have nothing to do with these gases, like that the cracking sound is actually your ligaments and tendons shifting after you apply force to your body, or that it happens because you don’t have much cartilage in the area that you “cracked,” so your joints can’t glide as smoothly as they should, per the Library of Congress. Whatever the mechanism behind cracking your back is, Dr. Anand says it likely applies to other areas you can crack, like your neck and knuckles.

For now, we’ll just have to file it as another unsolved mystery (along with Big Foot and your left sock that disappeared from the dryer again).

Is cracking your back bad for you?

Here’s the verdict: It’s not really good or bad to crack your back, but generally, it’s pretty harmless. “Ultimately, it doesn’t matter why this happens as long as it doesn’t hurt,” Dr. Asghar says.

As you age, you can start to experience normal wear and tear on the cartilage which makes it more difficult for your joints to glide smoothly, according to the Cleveland Clinic. When that happens, cracking your back can start to hurt, Dr. Asghar says.

That is a sign you should try to kick the habit before the situation becomes worse. If you are feeling back or neck pain and it’s not getting better (or it’s getting worse), stop cracking your back and talk to a doctor for the next best steps.

So, why does it feel so good to crack your back?

It’s not entirely known why cracking your back feels oh-so-good, but it might be nothing more than a stress reliever. If you’ve ever spent your day hunched over a computer (*raises hand*), maybe you’ve noticed a build-up of tightness in the muscles that surround your spine. One 2017 study published in the journal BMJ Open found that where your monitor is placed can even cause back pain. It turns out if your monitor is placed to the right or left of your computer (rather than directly in front of it), neck and back pain tends to be worse.

Here’s what could be going on: Your spinal cord is surrounded by groups of cells that send your brain information about things like pain and joint position, according to the National Institute of Neurological Disorders and Stroke. When you crack your back, your brain might interpret your back as being “better” and less tense than before, Dr. DeStefano says, so you might feel some sense of relief. An older study published in The Journal of the Canadian Chiropractic Association posits that the audible crack likely is more of a psychological benefit than a therapeutic one.

The thing is, most people keep cracking their backs because it makes them feel better, whether it comes down to a psychological effect or not, says Dr. Anand. There are some core exercises for lower back pain that can help, more on that next.

How to crack your back (safely)

If you really must try to crack your own back, it’s best to do so with a simple back pain exercise, like a seated chair twist. Here’s how to do it:

1. Sit up straight in a chair facing forward (that means hips, knees, and toes straight ahead).

2. Slowly twist your upper body to one side as far as you can comfortably stretch, but make sure to keep your hips and feet facing forward (and don’t lift up your bum).

3. Hold that stretch for a few seconds.

4. Return your upper body to the starting position.

5. Do the same movement to the other side.

You may or may not hear the coveted cracking sound, but rest assured, your back will still be happy. And if that particular exercise doesn’t help, there are other lower back stretches that might do the trick instead.

How do you get rid of a stiff back?

If a stiff back seems to be an everyday issue for you, there are a few other things you can do throughout the day, according to the Cleveland Clinic. One thing to try is changing the height of your computer screen mid-day—for proper ergonomic alignment, it should be directly in front of your face about 20 inches away. If you’re lucky enough to have a standing desk, you can just adjust that sucker to the standing height. If a standing desk isn’t in the cards, you can try propping your computer up on a box or a small shelf.

Another tip? Get up and move around every half hour or so, even on conference calls. Might as well get those steps in while you’re working, right? There are also tools you can use like foam rollers to help relieve lower back tension. (Hint: A great time for foam rolling is right before bed.)

Heat therapy (via a heating pad) and massage therapy are also worth a try, though, relief from back pain will likely be temporary.

Is getting a chiropractic adjustment good for your back?

When it comes to cracking your own back, you’re likely not going to hurt yourself, says Dr. Asghar, since you’ll instinctively want to protect yourself from harm. Here's a warning: When someone else does it for you, though, it’s a different story. The problem is that they may use too much force or move your body in an extreme direction, Dr. Anand says. “You can hurt your back if they don’t know what they’re doing,” he adds.

That’s why it’s important to see a professional, such as a licensed chiropractor, physical therapist, or osteopath if you want someone to crack your back. Back manipulation can be safe with a qualified professional, Dr. Asghar says, and is one of many tools that can be used for chronic back pain. In fact, a 2018 study published in the Spine Journal found that spinal manipulation and mobilization (a gentler technique than manipulation) was both safe and effective for lower back pain, specifically.

The post What Happens When You Crack Your Back? appeared first on SELF.