That Popping Sound in Your Joints – Should You Be Worried?

Your knee clicks when you go up stairs. Your neck cracks when you turn your head. Your hip clunks every time you get out of a chair. You’ve probably wondered, at least once, whether any of this means something is wrong.

The short answer is: usually not. But the longer answer is more useful – because there are situations where joint noises do deserve attention, and knowing the difference can save you a lot of unnecessary anxiety on one end, and missed warning signs on the other.

Why Joints Make Noise

Not all joint sounds are created equal, and they don’t all come from the same place. There are a few distinct mechanisms behind the pops, clicks, and clunks most people experience.

Cavitation: the classic “crack.” Joints are surrounded by a capsule filled with synovial fluid, which lubricates and nourishes the joint. That fluid contains dissolved gases. When a joint is moved in a way that rapidly changes the pressure inside the capsule – like when you crack your knuckles, or a chiropractor manipulates a spinal joint – a gas bubble forms and collapses almost instantaneously. That collapse produces a sharp, satisfying pop.

This is the same mechanism behind the noise when a joint is manipulated in physical therapy. It is not bones grinding. It is not damaged. Cavitation pops tend to be singular, meaning that once you’ve popped a joint, there’s a refractory period before it can pop again.

Tendon or ligament movement. Tendons and ligaments sometimes shift over bony prominences during movement, producing a snapping or clicking sensation. This is particularly common at the hip, shoulder, ankle, and knee.

These sounds tend to be repeatable: the same movement, in the same position, produces the same snap every time. On their own, without pain, they are almost always benign.

Joint surface changes. In joints with some degree of cartilage wear – which is extremely common and doesn’t necessarily cause symptoms – the surfaces may be slightly less smooth than they once were. Movement can produce a softer, more diffuse grinding or crunching sensation, called crepitus. This is common in knees, particularly under the kneecap, and in the shoulders.

Crepitus on its own, without pain or swelling, is generally not clinically significant. Many people with significant crepitus have no symptoms whatsoever.

When Joint Noises Are Nothing to Worry About

The vast majority of joint sounds, like the morning knuckle cracks, the knee that clicks going downstairs, and the neck that pops when you stretch, are benign. These are key indicators that a noise is not a problem:

No pain. A joint that clicks, pops, or snaps without producing pain is almost never a clinical concern, regardless of how loud or frequent the noise is.

No swelling. An absence of swelling alongside the noise is reassuring. Swelling indicates the joint is responding to something – whether that be irritation, inflammation, or injury.

No change in function. If the joint moves normally, bears load normally, and doesn’t give way, the noise alone is not a red flag.

This is worth stating plainly because joint sounds cause a disproportionate amount of anxiety. Many patients come in convinced that their clicking knee means their cartilage is being destroyed. In most cases, it isn’t – and reassurance, backed by a proper assessment, is genuinely valuable.

When to Pay Attention

There are circumstances where joint noises do warrant clinical attention – not because the noise itself is dangerous, but because of what may be accompanying it.

Pain with the noise. A click or pop that consistently produces pain, or that occurs in the context of a painful joint, is a different story from a pain-free one. The noise isn’t necessarily the problem, but the pain signals that something in the joint is being loaded in a way that is provoking it.

A new noise after an injury. If a joint that was previously quiet starts making noise after a trauma, such as a twisted knee, a fall, or a collision, that new sound in the context of injury deserves evaluation. In the knee, a pop at the time of injury is classically associated with ACL rupture. A new clicking or clunking after an ankle sprain can indicate ligamentous instability. Context matters enormously.

Locking or catching. If a joint doesn’t just click but also momentarily locks up, catches, or gives way, that’s a mechanical symptom that warrants a proper look. In the knee, this can indicate a meniscal tear or loose body. In the shoulder, it can indicate labral pathology.

Swelling accompanies the noise. Persistent or recurrent swelling in a joint, especially alongside noise, is a signal that the joint is being repeatedly irritated. The swelling is the body’s response – and it should be investigated.

Progressively worsening noise or sensation. A pop that has been there for years and never changed is very different from a grinding sensation that has been getting worse over months. Progression is meaningful.

A Note on Knees Specifically

The knee generates more anxiety around joint noise than perhaps any other joint, partly because it’s load-bearing and partly because knee sounds can be quite pronounced.

The crunch or grinding feeling under the kneecap, or patellofemoral crepitus, is extraordinarily common. Studies using sensitive equipment find it in the majority of adults, including those with no knee pain at all. By itself, it means very little.

Where it becomes relevant is when it accompanies pain, particularly pain with prolonged sitting, going up or down stairs, or squatting – the classic presentation of patellofemoral pain syndrome, which is very treatable. The crepitus in that context isn’t the cause of the problem; it’s just a feature of the joint that was already there.

What This Means Practically

If your joints are noisy but pain-free, you almost certainly do not need to be concerned. If your joints are noisy and painful, or if you’ve noticed a new noise after an injury, or if a joint locks, swells, or gives way, those are the things worth getting assessed. The noise is often just a useful additional piece of information in what is really a broader clinical picture.

At Aureum Physio, we assess joint symptoms in their full context. A popping knee with pain and a popping knee without pain are completely different clinical presentations that warrant completely different responses. Getting that distinction right, rather than either dismissing everything or over-investigating every creak, is exactly what a proper assessment is for.

If you have a joint that’s been bothering you – noisy or not – we’re happy to take a look and give you a clear picture of what’s actually going on.